[New pcre2 version] WikiCleanerBot: v2.04b - Bot T20 CW#61 - Fix errors for CW project (Reference before punctuation) #20
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dscho
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Jul 14, 2021
ibuf can be reused for multiple iterations of the loop. Specifically:
deflate() overwrites s.avail_in to show how much of the input buffer
has not been processed yet - and sometimes leaves 'avail_in > 0', in
which case ibuf will be processed again during the loop's subsequent
iteration.
But if we declare ibuf within the loop, then (in theory) we get a new
(and uninitialised) buffer for every iteration. In practice, my compiler
seems to resue the same buffer - meaning that this code does work - but
it doesn't seem safe to rely on this behaviour. MSAN correctly catches
this issue - as soon as we hit the 's.avail_in > 0' condition, we end up
reading from what seems to be uninitialised memory.
Therefore, we move ibuf out of the loop, making this reuse safe.
See MSAN output from t1050-large below - the interesting part is the
ibuf creation at the end, although there's a lot of indirection before
we reach the read from unitialised memory:
==11294==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x7f75db58fb1c in crc32_little crc32.c:283:9
#1 0x7f75db58d5b3 in crc32_z crc32.c:220:20
#2 0x7f75db59668c in crc32 crc32.c:242:12
#3 0x8c94f8 in hashwrite csum-file.c:101:15
#4 0x825faf in stream_to_pack bulk-checkin.c:154:5
#5 0x82467b in deflate_to_pack bulk-checkin.c:225:8
#6 0x823ff1 in index_bulk_checkin bulk-checkin.c:264:15
#7 0xa7cff2 in index_stream object-file.c:2234:9
#8 0xa7bff7 in index_fd object-file.c:2256:9
#9 0xa7d22d in index_path object-file.c:2274:7
#10 0xb3c8c9 in add_to_index read-cache.c:802:7
#11 0xb3e039 in add_file_to_index read-cache.c:835:9
#12 0x4a99c3 in add_files add.c:458:7
#13 0x4a7276 in cmd_add add.c:670:18
#14 0x4a1e76 in run_builtin git.c:461:11
#15 0x49e1e7 in handle_builtin git.c:714:3
#16 0x4a0c08 in run_argv git.c:781:4
#17 0x49d5a8 in cmd_main git.c:912:19
#18 0x7974da in main common-main.c:52:11
#19 0x7f75da66f349 in __libc_start_main (/lib64/libc.so.6+0x24349)
#20 0x421bd9 in _start start.S:120
Uninitialized value was stored to memory at
#0 0x7f75db58fa6b in crc32_little crc32.c:283:9
#1 0x7f75db58d5b3 in crc32_z crc32.c:220:20
#2 0x7f75db59668c in crc32 crc32.c:242:12
#3 0x8c94f8 in hashwrite csum-file.c:101:15
#4 0x825faf in stream_to_pack bulk-checkin.c:154:5
#5 0x82467b in deflate_to_pack bulk-checkin.c:225:8
#6 0x823ff1 in index_bulk_checkin bulk-checkin.c:264:15
#7 0xa7cff2 in index_stream object-file.c:2234:9
#8 0xa7bff7 in index_fd object-file.c:2256:9
#9 0xa7d22d in index_path object-file.c:2274:7
#10 0xb3c8c9 in add_to_index read-cache.c:802:7
#11 0xb3e039 in add_file_to_index read-cache.c:835:9
#12 0x4a99c3 in add_files add.c:458:7
#13 0x4a7276 in cmd_add add.c:670:18
#14 0x4a1e76 in run_builtin git.c:461:11
#15 0x49e1e7 in handle_builtin git.c:714:3
#16 0x4a0c08 in run_argv git.c:781:4
#17 0x49d5a8 in cmd_main git.c:912:19
#18 0x7974da in main common-main.c:52:11
#19 0x7f75da66f349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Uninitialized value was stored to memory at
#0 0x447eb9 in __msan_memcpy msan_interceptors.cpp:1558:3
#1 0x7f75db5c2011 in flush_pending deflate.c:746:5
#2 0x7f75db5cafa0 in deflate_stored deflate.c:1815:9
#3 0x7f75db5bb7d2 in deflate deflate.c:1005:34
#4 0xd80b7f in git_deflate zlib.c:244:12
#5 0x825dff in stream_to_pack bulk-checkin.c:140:12
#6 0x82467b in deflate_to_pack bulk-checkin.c:225:8
#7 0x823ff1 in index_bulk_checkin bulk-checkin.c:264:15
#8 0xa7cff2 in index_stream object-file.c:2234:9
#9 0xa7bff7 in index_fd object-file.c:2256:9
#10 0xa7d22d in index_path object-file.c:2274:7
#11 0xb3c8c9 in add_to_index read-cache.c:802:7
#12 0xb3e039 in add_file_to_index read-cache.c:835:9
#13 0x4a99c3 in add_files add.c:458:7
#14 0x4a7276 in cmd_add add.c:670:18
#15 0x4a1e76 in run_builtin git.c:461:11
#16 0x49e1e7 in handle_builtin git.c:714:3
#17 0x4a0c08 in run_argv git.c:781:4
#18 0x49d5a8 in cmd_main git.c:912:19
#19 0x7974da in main common-main.c:52:11
Uninitialized value was stored to memory at
#0 0x447eb9 in __msan_memcpy msan_interceptors.cpp:1558:3
#1 0x7f75db644241 in _tr_stored_block trees.c:873:5
#2 0x7f75db5cad7c in deflate_stored deflate.c:1813:9
#3 0x7f75db5bb7d2 in deflate deflate.c:1005:34
#4 0xd80b7f in git_deflate zlib.c:244:12
#5 0x825dff in stream_to_pack bulk-checkin.c:140:12
#6 0x82467b in deflate_to_pack bulk-checkin.c:225:8
#7 0x823ff1 in index_bulk_checkin bulk-checkin.c:264:15
#8 0xa7cff2 in index_stream object-file.c:2234:9
#9 0xa7bff7 in index_fd object-file.c:2256:9
#10 0xa7d22d in index_path object-file.c:2274:7
#11 0xb3c8c9 in add_to_index read-cache.c:802:7
#12 0xb3e039 in add_file_to_index read-cache.c:835:9
#13 0x4a99c3 in add_files add.c:458:7
#14 0x4a7276 in cmd_add add.c:670:18
#15 0x4a1e76 in run_builtin git.c:461:11
#16 0x49e1e7 in handle_builtin git.c:714:3
#17 0x4a0c08 in run_argv git.c:781:4
#18 0x49d5a8 in cmd_main git.c:912:19
#19 0x7974da in main common-main.c:52:11
Uninitialized value was stored to memory at
#0 0x447eb9 in __msan_memcpy msan_interceptors.cpp:1558:3
#1 0x7f75db5c8fcf in deflate_stored deflate.c:1783:9
#2 0x7f75db5bb7d2 in deflate deflate.c:1005:34
#3 0xd80b7f in git_deflate zlib.c:244:12
#4 0x825dff in stream_to_pack bulk-checkin.c:140:12
#5 0x82467b in deflate_to_pack bulk-checkin.c:225:8
#6 0x823ff1 in index_bulk_checkin bulk-checkin.c:264:15
#7 0xa7cff2 in index_stream object-file.c:2234:9
#8 0xa7bff7 in index_fd object-file.c:2256:9
#9 0xa7d22d in index_path object-file.c:2274:7
#10 0xb3c8c9 in add_to_index read-cache.c:802:7
#11 0xb3e039 in add_file_to_index read-cache.c:835:9
#12 0x4a99c3 in add_files add.c:458:7
#13 0x4a7276 in cmd_add add.c:670:18
#14 0x4a1e76 in run_builtin git.c:461:11
#15 0x49e1e7 in handle_builtin git.c:714:3
#16 0x4a0c08 in run_argv git.c:781:4
#17 0x49d5a8 in cmd_main git.c:912:19
#18 0x7974da in main common-main.c:52:11
#19 0x7f75da66f349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Uninitialized value was stored to memory at
#0 0x447eb9 in __msan_memcpy msan_interceptors.cpp:1558:3
#1 0x7f75db5ea545 in read_buf deflate.c:1181:5
#2 0x7f75db5c97f7 in deflate_stored deflate.c:1791:9
#3 0x7f75db5bb7d2 in deflate deflate.c:1005:34
#4 0xd80b7f in git_deflate zlib.c:244:12
#5 0x825dff in stream_to_pack bulk-checkin.c:140:12
#6 0x82467b in deflate_to_pack bulk-checkin.c:225:8
#7 0x823ff1 in index_bulk_checkin bulk-checkin.c:264:15
#8 0xa7cff2 in index_stream object-file.c:2234:9
#9 0xa7bff7 in index_fd object-file.c:2256:9
#10 0xa7d22d in index_path object-file.c:2274:7
#11 0xb3c8c9 in add_to_index read-cache.c:802:7
#12 0xb3e039 in add_file_to_index read-cache.c:835:9
#13 0x4a99c3 in add_files add.c:458:7
#14 0x4a7276 in cmd_add add.c:670:18
#15 0x4a1e76 in run_builtin git.c:461:11
#16 0x49e1e7 in handle_builtin git.c:714:3
#17 0x4a0c08 in run_argv git.c:781:4
#18 0x49d5a8 in cmd_main git.c:912:19
#19 0x7974da in main common-main.c:52:11
Uninitialized value was created by an allocation of 'ibuf' in the stack frame of function 'stream_to_pack'
#0 0x825710 in stream_to_pack bulk-checkin.c:101
SUMMARY: MemorySanitizer: use-of-uninitialized-value crc32.c:283:9 in crc32_little
Exiting
Signed-off-by: Andrzej Hunt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this issue
Oct 27, 2021
In a sparse index it is possible for the tree that is being verified
to be freed while it is being verified. This happens when the index is
sparse but the cache tree is not and index_name_pos() looks up a path
from the cache tree that is a descendant of a sparse index entry. That
triggers a call to ensure_full_index() which frees the cache tree that
is being verified. Carrying on trying to verify the tree after this
results in a use-after-free bug. Instead restart the verification if a
sparse index is converted to a full index. This bug is triggered by a
call to reset_head() in "git rebase --apply". Thanks to René Scharfe
and Derrick Stolee for their help analyzing the problem.
==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080
READ of size 4 at 0x606000001b20 thread T0
#0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863
#1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
#14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d)
0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58)
freed by thread T0 here:
#0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127
#1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35
#2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310
#6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588
#7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850
#8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
previously allocated by thread T0 here:
#0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140
#2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17
#3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763
#4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779
#7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85
#8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
Signed-off-by: Phillip Wood <[email protected]>
Signed-off-by: Derrick Stolee <[email protected]>
dscho
pushed a commit
that referenced
this issue
Nov 2, 2021
In a sparse index it is possible for the tree that is being verified
to be freed while it is being verified. This happens when the index is
sparse but the cache tree is not and index_name_pos() looks up a path
from the cache tree that is a descendant of a sparse index entry. That
triggers a call to ensure_full_index() which frees the cache tree that
is being verified. Carrying on trying to verify the tree after this
results in a use-after-free bug. Instead restart the verification if a
sparse index is converted to a full index. This bug is triggered by a
call to reset_head() in "git rebase --apply". Thanks to René Scharfe
and Derrick Stolee for their help analyzing the problem.
==74345==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000001b20 at pc 0x557cbe82d3a2 bp 0x7ffdfee08090 sp 0x7ffdfee08080
READ of size 4 at 0x606000001b20 thread T0
#0 0x557cbe82d3a1 in verify_one /home/phil/src/git/cache-tree.c:863
#1 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#2 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#3 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#4 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#5 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#6 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#7 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#8 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#9 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#10 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#11 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#12 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#13 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
#14 0x557cbe5bcb8d in _start (/home/phil/src/git/git+0x1b9b8d)
0x606000001b20 is located 0 bytes inside of 56-byte region [0x606000001b20,0x606000001b58)
freed by thread T0 here:
#0 0x7fdd4bacff19 in __interceptor_free /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:127
#1 0x557cbe82af60 in cache_tree_free /home/phil/src/git/cache-tree.c:35
#2 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#3 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#4 0x557cbe82aee5 in cache_tree_free /home/phil/src/git/cache-tree.c:31
#5 0x557cbeb2557a in ensure_full_index /home/phil/src/git/sparse-index.c:310
#6 0x557cbea45c4a in index_name_stage_pos /home/phil/src/git/read-cache.c:588
#7 0x557cbe82ce37 in verify_one /home/phil/src/git/cache-tree.c:850
#8 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#9 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#10 0x557cbe82ca9d in verify_one /home/phil/src/git/cache-tree.c:840
#11 0x557cbe830a2b in cache_tree_verify /home/phil/src/git/cache-tree.c:910
#12 0x557cbea53741 in write_locked_index /home/phil/src/git/read-cache.c:3250
#13 0x557cbeab7fdd in reset_head /home/phil/src/git/reset.c:87
#14 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#15 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#16 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#17 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#18 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#19 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#20 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
previously allocated by thread T0 here:
#0 0x7fdd4bad0459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x557cbebc1807 in xcalloc /home/phil/src/git/wrapper.c:140
#2 0x557cbe82b7d8 in cache_tree /home/phil/src/git/cache-tree.c:17
#3 0x557cbe82b7d8 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:763
#4 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#5 0x557cbe82b837 in prime_cache_tree_rec /home/phil/src/git/cache-tree.c:764
#6 0x557cbe8304e1 in prime_cache_tree /home/phil/src/git/cache-tree.c:779
#7 0x557cbeab7fa7 in reset_head /home/phil/src/git/reset.c:85
#8 0x557cbe72147f in cmd_rebase builtin/rebase.c:2074
#9 0x557cbe5bd151 in run_builtin /home/phil/src/git/git.c:461
#10 0x557cbe5bd151 in handle_builtin /home/phil/src/git/git.c:714
#11 0x557cbe5c0503 in run_argv /home/phil/src/git/git.c:781
#12 0x557cbe5c0503 in cmd_main /home/phil/src/git/git.c:912
#13 0x557cbe5bad28 in main /home/phil/src/git/common-main.c:52
#14 0x7fdd4b82eb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
Signed-off-by: Phillip Wood <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this issue
Jan 23, 2023
It is possible to trigger an integer overflow when parsing attribute
names when there are more than 2^31 of them for a single pattern. This
can either lead to us dying due to trying to request too many bytes:
blob=$(perl -e 'print "f" . " a=" x 2147483649' | git hash-object -w --stdin)
git update-index --add --cacheinfo 100644,$blob,.gitattributes
git attr-check --all file
=================================================================
==1022==ERROR: AddressSanitizer: requested allocation size 0xfffffff800000032 (0xfffffff800001038 after adjustments for alignment, red zones etc.) exceeds maximum supported size of 0x10000000000 (thread T0)
#0 0x7fd3efabf411 in __interceptor_calloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77
#1 0x5563a0a1e3d3 in xcalloc wrapper.c:150
#2 0x5563a058d005 in parse_attr_line attr.c:384
#3 0x5563a058e661 in handle_attr_line attr.c:660
#4 0x5563a058eddb in read_attr_from_index attr.c:769
#5 0x5563a058ef12 in read_attr attr.c:797
#6 0x5563a058f24c in bootstrap_attr_stack attr.c:867
#7 0x5563a058f4a3 in prepare_attr_stack attr.c:902
#8 0x5563a05905da in collect_some_attrs attr.c:1097
#9 0x5563a059093d in git_all_attrs attr.c:1128
#10 0x5563a02f636e in check_attr builtin/check-attr.c:67
#11 0x5563a02f6c12 in cmd_check_attr builtin/check-attr.c:183
#12 0x5563a02aa993 in run_builtin git.c:466
#13 0x5563a02ab397 in handle_builtin git.c:721
#14 0x5563a02abb2b in run_argv git.c:788
#15 0x5563a02ac991 in cmd_main git.c:926
#16 0x5563a05432bd in main common-main.c:57
#17 0x7fd3ef82228f (/usr/lib/libc.so.6+0x2328f)
==1022==HINT: if you don't care about these errors you may set allocator_may_return_null=1
SUMMARY: AddressSanitizer: allocation-size-too-big /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77 in __interceptor_calloc
==1022==ABORTING
Or, much worse, it can lead to an out-of-bounds write because we
underallocate and then memcpy(3P) into an array:
perl -e '
print "A " . "\rh="x2000000000;
print "\rh="x2000000000;
print "\rh="x294967294 . "\n"
' >.gitattributes
git add .gitattributes
git commit -am "evil attributes"
$ git clone --quiet /path/to/repo
=================================================================
==15062==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000002550 at pc 0x5555559884d5 bp 0x7fffffffbc60 sp 0x7fffffffbc58
WRITE of size 8 at 0x602000002550 thread T0
#0 0x5555559884d4 in parse_attr_line attr.c:393
#1 0x5555559884d4 in handle_attr_line attr.c:660
#2 0x555555988902 in read_attr_from_index attr.c:784
#3 0x555555988902 in read_attr_from_index attr.c:747
#4 0x555555988a1d in read_attr attr.c:800
#5 0x555555989b0c in bootstrap_attr_stack attr.c:882
#6 0x555555989b0c in prepare_attr_stack attr.c:917
#7 0x555555989b0c in collect_some_attrs attr.c:1112
#8 0x55555598b141 in git_check_attr attr.c:1126
#9 0x555555a13004 in convert_attrs convert.c:1311
#10 0x555555a95e04 in checkout_entry_ca entry.c:553
#11 0x555555d58bf6 in checkout_entry entry.h:42
#12 0x555555d58bf6 in check_updates unpack-trees.c:480
#13 0x555555d5eb55 in unpack_trees unpack-trees.c:2040
#14 0x555555785ab7 in checkout builtin/clone.c:724
#15 0x555555785ab7 in cmd_clone builtin/clone.c:1384
#16 0x55555572443c in run_builtin git.c:466
#17 0x55555572443c in handle_builtin git.c:721
#18 0x555555727872 in run_argv git.c:788
#19 0x555555727872 in cmd_main git.c:926
#20 0x555555721fa0 in main common-main.c:57
#21 0x7ffff73f1d09 in __libc_start_main ../csu/libc-start.c:308
#22 0x555555723f39 in _start (git+0x1cff39)
0x602000002552 is located 0 bytes to the right of 2-byte region [0x602000002550,0x602000002552) allocated by thread T0 here:
#0 0x7ffff768c037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x555555d7fff7 in xcalloc wrapper.c:150
#2 0x55555598815f in parse_attr_line attr.c:384
#3 0x55555598815f in handle_attr_line attr.c:660
#4 0x555555988902 in read_attr_from_index attr.c:784
#5 0x555555988902 in read_attr_from_index attr.c:747
#6 0x555555988a1d in read_attr attr.c:800
#7 0x555555989b0c in bootstrap_attr_stack attr.c:882
#8 0x555555989b0c in prepare_attr_stack attr.c:917
#9 0x555555989b0c in collect_some_attrs attr.c:1112
#10 0x55555598b141 in git_check_attr attr.c:1126
#11 0x555555a13004 in convert_attrs convert.c:1311
#12 0x555555a95e04 in checkout_entry_ca entry.c:553
#13 0x555555d58bf6 in checkout_entry entry.h:42
#14 0x555555d58bf6 in check_updates unpack-trees.c:480
#15 0x555555d5eb55 in unpack_trees unpack-trees.c:2040
#16 0x555555785ab7 in checkout builtin/clone.c:724
#17 0x555555785ab7 in cmd_clone builtin/clone.c:1384
#18 0x55555572443c in run_builtin git.c:466
#19 0x55555572443c in handle_builtin git.c:721
#20 0x555555727872 in run_argv git.c:788
#21 0x555555727872 in cmd_main git.c:926
#22 0x555555721fa0 in main common-main.c:57
#23 0x7ffff73f1d09 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: heap-buffer-overflow attr.c:393 in parse_attr_line
Shadow bytes around the buggy address:
0x0c047fff8450: fa fa 00 02 fa fa 00 07 fa fa fd fd fa fa 00 00
0x0c047fff8460: fa fa 02 fa fa fa fd fd fa fa 00 06 fa fa 05 fa
0x0c047fff8470: fa fa fd fd fa fa 00 02 fa fa 06 fa fa fa 05 fa
0x0c047fff8480: fa fa 07 fa fa fa fd fd fa fa 00 01 fa fa 00 02
0x0c047fff8490: fa fa 00 03 fa fa 00 fa fa fa 00 01 fa fa 00 03
=>0x0c047fff84a0: fa fa 00 01 fa fa 00 02 fa fa[02]fa fa fa fa fa
0x0c047fff84b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff84f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Shadow gap: cc
==15062==ABORTING
Fix this bug by using `size_t` instead to count the number of attributes
so that this value cannot reasonably overflow without running out of
memory before already.
Reported-by: Markus Vervier <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this issue
Jan 23, 2023
When using a padding specifier in the pretty format passed to git-log(1)
we need to calculate the string length in several places. These string
lengths are stored in `int`s though, which means that these can easily
overflow when the input lengths exceeds 2GB. This can ultimately lead to
an out-of-bounds write when these are used in a call to memcpy(3P):
==8340==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7f1ec62f97fe at pc 0x7f2127e5f427 bp 0x7ffd3bd63de0 sp 0x7ffd3bd63588
WRITE of size 1 at 0x7f1ec62f97fe thread T0
#0 0x7f2127e5f426 in __interceptor_memcpy /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
#1 0x5628e96aa605 in format_and_pad_commit pretty.c:1762
#2 0x5628e96aa7f4 in format_commit_item pretty.c:1801
#3 0x5628e97cdb24 in strbuf_expand strbuf.c:429
#4 0x5628e96ab060 in repo_format_commit_message pretty.c:1869
#5 0x5628e96acd0f in pretty_print_commit pretty.c:2161
#6 0x5628e95a44c8 in show_log log-tree.c:781
#7 0x5628e95a76ba in log_tree_commit log-tree.c:1117
#8 0x5628e922bed5 in cmd_log_walk_no_free builtin/log.c:508
#9 0x5628e922c35b in cmd_log_walk builtin/log.c:549
#10 0x5628e922f1a2 in cmd_log builtin/log.c:883
#11 0x5628e9106993 in run_builtin git.c:466
#12 0x5628e9107397 in handle_builtin git.c:721
#13 0x5628e9107b07 in run_argv git.c:788
#14 0x5628e91088a7 in cmd_main git.c:923
#15 0x5628e939d682 in main common-main.c:57
#16 0x7f2127c3c28f (/usr/lib/libc.so.6+0x2328f)
#17 0x7f2127c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#18 0x5628e91020e4 in _start ../sysdeps/x86_64/start.S:115
0x7f1ec62f97fe is located 2 bytes to the left of 4831838265-byte region [0x7f1ec62f9800,0x7f1fe62f9839)
allocated by thread T0 here:
#0 0x7f2127ebe7ea in __interceptor_realloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:85
#1 0x5628e98774d4 in xrealloc wrapper.c:136
#2 0x5628e97cb01c in strbuf_grow strbuf.c:99
#3 0x5628e97ccd42 in strbuf_addchars strbuf.c:327
#4 0x5628e96aa55c in format_and_pad_commit pretty.c:1761
#5 0x5628e96aa7f4 in format_commit_item pretty.c:1801
#6 0x5628e97cdb24 in strbuf_expand strbuf.c:429
#7 0x5628e96ab060 in repo_format_commit_message pretty.c:1869
#8 0x5628e96acd0f in pretty_print_commit pretty.c:2161
#9 0x5628e95a44c8 in show_log log-tree.c:781
#10 0x5628e95a76ba in log_tree_commit log-tree.c:1117
#11 0x5628e922bed5 in cmd_log_walk_no_free builtin/log.c:508
#12 0x5628e922c35b in cmd_log_walk builtin/log.c:549
#13 0x5628e922f1a2 in cmd_log builtin/log.c:883
#14 0x5628e9106993 in run_builtin git.c:466
#15 0x5628e9107397 in handle_builtin git.c:721
#16 0x5628e9107b07 in run_argv git.c:788
#17 0x5628e91088a7 in cmd_main git.c:923
#18 0x5628e939d682 in main common-main.c:57
#19 0x7f2127c3c28f (/usr/lib/libc.so.6+0x2328f)
#20 0x7f2127c3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#21 0x5628e91020e4 in _start ../sysdeps/x86_64/start.S:115
SUMMARY: AddressSanitizer: heap-buffer-overflow /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy
Shadow bytes around the buggy address:
0x0fe458c572a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0fe458c572e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0fe458c572f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa[fa]
0x0fe458c57300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57310: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57330: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe458c57340: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==8340==ABORTING
The pretty format can also be used in `git archive` operations via the
`export-subst` attribute. So this is what in our opinion makes this a
critical issue in the context of Git forges which allow to download an
archive of user supplied Git repositories.
Fix this vulnerability by using `size_t` instead of `int` to track the
string lengths. Add tests which detect this vulnerability when Git is
compiled with the address sanitizer.
Reported-by: Joern Schneeweisz <[email protected]>
Original-patch-by: Joern Schneeweisz <[email protected]>
Modified-by: Taylor Blau <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
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Sep 13, 2024
It was recently reported that concurrent reads and writes may cause the
reftable backend to segfault. The root cause of this is that we do not
properly keep track of reftable readers across reloads.
Suppose that you have a reftable iterator and then decide to reload the
stack while iterating through the iterator. When the stack has been
rewritten since we have created the iterator, then we would end up
discarding a subset of readers that may still be in use by the iterator.
The consequence is that we now try to reference deallocated memory,
which of course segfaults.
One way to trigger this is in t5616, where some background maintenance
jobs have been leaking from one test into another. This leads to stack
traces like the following one:
+ git -c protocol.version=0 -C pc1 fetch --filter=blob:limit=29999 --refetch origin
AddressSanitizer:DEADLYSIGNAL
=================================================================
==657994==ERROR: AddressSanitizer: SEGV on unknown address 0x7fa0f0ec6089 (pc 0x55f23e52ddf9 bp
0x7ffe7bfa1700 sp 0x7ffe7bfa1700 T0)
==657994==The signal is caused by a READ memory access.
#0 0x55f23e52ddf9 in get_var_int reftable/record.c:29
#1 0x55f23e53295e in reftable_decode_keylen reftable/record.c:170
#2 0x55f23e532cc0 in reftable_decode_key reftable/record.c:194
#3 0x55f23e54e72e in block_iter_next reftable/block.c:398
#4 0x55f23e5573dc in table_iter_next_in_block reftable/reader.c:240
#5 0x55f23e5573dc in table_iter_next reftable/reader.c:355
#6 0x55f23e5573dc in table_iter_next reftable/reader.c:339
#7 0x55f23e551283 in merged_iter_advance_subiter reftable/merged.c:69
#8 0x55f23e55169e in merged_iter_next_entry reftable/merged.c:123
#9 0x55f23e55169e in merged_iter_next_void reftable/merged.c:172
#10 0x55f23e537625 in reftable_iterator_next_ref reftable/generic.c:175
#11 0x55f23e2cf9c6 in reftable_ref_iterator_advance refs/reftable-backend.c:464
#12 0x55f23e2d996e in ref_iterator_advance refs/iterator.c:13
#13 0x55f23e2d996e in do_for_each_ref_iterator refs/iterator.c:452
#14 0x55f23dca6767 in get_ref_map builtin/fetch.c:623
#15 0x55f23dca6767 in do_fetch builtin/fetch.c:1659
#16 0x55f23dca6767 in fetch_one builtin/fetch.c:2133
#17 0x55f23dca6767 in cmd_fetch builtin/fetch.c:2432
#18 0x55f23dba7764 in run_builtin git.c:484
#19 0x55f23dba7764 in handle_builtin git.c:741
#20 0x55f23dbab61e in run_argv git.c:805
#21 0x55f23dbab61e in cmd_main git.c:1000
#22 0x55f23dba4781 in main common-main.c:64
#23 0x7fa0f063fc89 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#24 0x7fa0f063fd44 in __libc_start_main_impl ../csu/libc-start.c:360
#25 0x55f23dba6ad0 in _start (git+0xadfad0) (BuildId: 803b2b7f59beb03d7849fb8294a8e2145dd4aa27)
While it is somewhat awkward that the maintenance processes survive
tests in the first place, it is totally expected that reftables should
work alright with concurrent writers. Seemingly they don't.
The only underlying resource that we need to care about in this context
is the reftable reader, which is responsible for reading a single table
from disk. These readers get discarded immediately (unless reused) when
calling `reftable_stack_reload()`, which is wrong. We can only close
them once we know that there are no iterators using them anymore.
Prepare for a fix by converting the reftable readers to be refcounted.
Reported-by: Jeff King <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
dscho
added a commit
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Oct 21, 2024
An internal customer reported a segfault when running `git sparse-checkout set` with the `index.sparse` config enabled. I was unable to reproduce it locally, but with their help we debugged into the failing process and discovered the following stacktrace: ``` #0 0x00007ff6318fb7b0 in rehash (map=0x3dfb00d0440, newsize=1048576) at hashmap.c:125 #1 0x00007ff6318fbc66 in hashmap_add (map=0x3dfb00d0440, entry=0x3dfb5c58bc8) at hashmap.c:247 #2 0x00007ff631937a70 in hash_index_entry (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:122 #3 0x00007ff631938a2f in add_name_hash (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:638 #4 0x00007ff631a064de in set_index_entry (istate=0x3dfb00d0400, nr=8291, ce=0x3dfb5c58bc8) at sparse-index.c:255 #5 0x00007ff631a06692 in add_path_to_index (oid=0x5ff130, base=0x5ff580, path=0x3dfb4b725da "<redacted>", mode=33188, context=0x5ff570) at sparse-index.c:307 #6 0x00007ff631a3b48c in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41f60, base=0x5ff580, depth=2, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:46 #7 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41e80, base=0x5ff580, depth=1, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #8 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41ac8, base=0x5ff580, depth=0, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #9 0x00007ff631a06a95 in expand_index (istate=0x3dfb00d0100, pl=0x0) at sparse-index.c:422 #10 0x00007ff631a06cbd in ensure_full_index (istate=0x3dfb00d0100) at sparse-index.c:456 #11 0x00007ff631990d08 in index_name_stage_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21, stage=0, search_mode=EXPAND_SPARSE) at read-cache.c:556 #12 0x00007ff631990d6c in index_name_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21) at read-cache.c:566 #13 0x00007ff63180dbb5 in sanitize_paths (argc=185, argv=0x3dfb0030018, prefix=0x0, skip_checks=0) at builtin/sparse-checkout.c:756 #14 0x00007ff63180de50 in sparse_checkout_set (argc=185, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:860 #15 0x00007ff63180e6c5 in cmd_sparse_checkout (argc=186, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:1063 #16 0x00007ff6317234cb in run_builtin (p=0x7ff631ad9b38 <commands+2808>, argc=187, argv=0x3dfb0030018) at git.c:548 #17 0x00007ff6317239c0 in handle_builtin (argc=187, argv=0x3dfb0030018) at git.c:808 #18 0x00007ff631723c7d in run_argv (argcp=0x5ffdd0, argv=0x5ffd78) at git.c:877 #19 0x00007ff6317241d1 in cmd_main (argc=187, argv=0x3dfb0030018) at git.c:1017 #20 0x00007ff631838b60 in main (argc=190, argv=0x3dfb0030000) at common-main.c:64 ``` The very bottom of the stack being the `rehash()` method from `hashmap.c` as called within the `name-hash` API made me look at where these hashmaps were being used in the sparse index logic. These were being copied across indexes, which seems dangerous. Indeed, clearing these hashmaps and setting them as not initialized fixes the segfault. The second commit is a response to a test failure that happens in `t1092-sparse-checkout-compatibility.sh` where `git stash pop` starts to fail because the underlying `git checkout-index` process fails due to colliding files. Passing the `-f` flag appears to work, but it's unclear why this name-hash change causes that change in behavior.
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Jan 7, 2025
In 1b9e9be (csum-file.c: use unsafe SHA-1 implementation when available, 2024-09-26) we have converted our `struct hashfile` to use the unsafe SHA1 backend, which results in a significant speedup. One needs to be careful with how to use that structure now though because callers need to consistently use either the safe or unsafe variants of SHA1, as otherwise one can easily trigger corruption. As it turns out, we have one inconsistent usage in our tree because we directly initialize `struct hashfile_checkpoint::ctx` with the safe variant of SHA1, but end up writing to that context with the unsafe ones. This went unnoticed so far because our CI systems do not exercise different hash functions for these two backends, and consequently safe and unsafe variants are equivalent. But when using SHA1DC as safe and OpenSSL as unsafe backend this leads to a crash an t1050: ++ git -c core.compression=0 add large1 AddressSanitizer:DEADLYSIGNAL ================================================================= ==1367==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000040 (pc 0x7ffff7a01a99 bp 0x507000000db0 sp 0x7fffffff5690 T0) ==1367==The signal is caused by a READ memory access. ==1367==Hint: address points to the zero page. #0 0x7ffff7a01a99 in EVP_MD_CTX_copy_ex (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) #1 0x555555ddde56 in openssl_SHA1_Clone ../sha1/openssl.h:40:2 #2 0x555555dce2fc in git_hash_sha1_clone_unsafe ../object-file.c:123:2 #3 0x555555c2d5f8 in hashfile_checkpoint ../csum-file.c:211:2 #4 0x555555b9905d in deflate_blob_to_pack ../bulk-checkin.c:286:4 #5 0x555555b98ae9 in index_blob_bulk_checkin ../bulk-checkin.c:362:15 #6 0x555555ddab62 in index_blob_stream ../object-file.c:2756:9 #7 0x555555dda420 in index_fd ../object-file.c:2778:9 #8 0x555555ddad76 in index_path ../object-file.c:2796:7 #9 0x555555e947f3 in add_to_index ../read-cache.c:771:7 #10 0x555555e954a4 in add_file_to_index ../read-cache.c:804:9 #11 0x5555558b5c39 in add_files ../builtin/add.c:355:7 #12 0x5555558b412e in cmd_add ../builtin/add.c:578:18 #13 0x555555b1f493 in run_builtin ../git.c:480:11 #14 0x555555b1bfef in handle_builtin ../git.c:740:9 #15 0x555555b1e6f4 in run_argv ../git.c:807:4 #16 0x555555b1b87a in cmd_main ../git.c:947:19 #17 0x5555561649e6 in main ../common-main.c:64:11 #18 0x7ffff742a1fb in __libc_start_call_main (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4) #19 0x7ffff742a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4) #20 0x555555772c84 in _start (git+0x21ec84) ==1367==Register values: rax = 0x0000511000001080 rbx = 0x0000000000000000 rcx = 0x000000000000000c rdx = 0x0000000000000000 rdi = 0x0000000000000000 rsi = 0x0000507000000db0 rbp = 0x0000507000000db0 rsp = 0x00007fffffff5690 r8 = 0x0000000000000000 r9 = 0x0000000000000000 r10 = 0x0000000000000000 r11 = 0x00007ffff7a01a30 r12 = 0x0000000000000000 r13 = 0x00007fffffff6b38 r14 = 0x00007ffff7ffd000 r15 = 0x00005555563b9910 AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) in EVP_MD_CTX_copy_ex ==1367==ABORTING ./test-lib.sh: line 1023: 1367 Aborted git $config add large1 error: last command exited with $?=134 not ok 4 - add with -c core.compression=0 Fix the issue by using the unsafe variant instead. Signed-off-by: Patrick Steinhardt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
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Feb 13, 2025
An internal customer reported a segfault when running `git sparse-checkout set` with the `index.sparse` config enabled. I was unable to reproduce it locally, but with their help we debugged into the failing process and discovered the following stacktrace: ``` #0 0x00007ff6318fb7b0 in rehash (map=0x3dfb00d0440, newsize=1048576) at hashmap.c:125 #1 0x00007ff6318fbc66 in hashmap_add (map=0x3dfb00d0440, entry=0x3dfb5c58bc8) at hashmap.c:247 #2 0x00007ff631937a70 in hash_index_entry (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:122 #3 0x00007ff631938a2f in add_name_hash (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:638 #4 0x00007ff631a064de in set_index_entry (istate=0x3dfb00d0400, nr=8291, ce=0x3dfb5c58bc8) at sparse-index.c:255 #5 0x00007ff631a06692 in add_path_to_index (oid=0x5ff130, base=0x5ff580, path=0x3dfb4b725da "<redacted>", mode=33188, context=0x5ff570) at sparse-index.c:307 #6 0x00007ff631a3b48c in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41f60, base=0x5ff580, depth=2, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:46 #7 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41e80, base=0x5ff580, depth=1, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #8 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41ac8, base=0x5ff580, depth=0, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #9 0x00007ff631a06a95 in expand_index (istate=0x3dfb00d0100, pl=0x0) at sparse-index.c:422 #10 0x00007ff631a06cbd in ensure_full_index (istate=0x3dfb00d0100) at sparse-index.c:456 #11 0x00007ff631990d08 in index_name_stage_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21, stage=0, search_mode=EXPAND_SPARSE) at read-cache.c:556 #12 0x00007ff631990d6c in index_name_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21) at read-cache.c:566 #13 0x00007ff63180dbb5 in sanitize_paths (argc=185, argv=0x3dfb0030018, prefix=0x0, skip_checks=0) at builtin/sparse-checkout.c:756 #14 0x00007ff63180de50 in sparse_checkout_set (argc=185, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:860 #15 0x00007ff63180e6c5 in cmd_sparse_checkout (argc=186, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:1063 #16 0x00007ff6317234cb in run_builtin (p=0x7ff631ad9b38 <commands+2808>, argc=187, argv=0x3dfb0030018) at git.c:548 #17 0x00007ff6317239c0 in handle_builtin (argc=187, argv=0x3dfb0030018) at git.c:808 #18 0x00007ff631723c7d in run_argv (argcp=0x5ffdd0, argv=0x5ffd78) at git.c:877 #19 0x00007ff6317241d1 in cmd_main (argc=187, argv=0x3dfb0030018) at git.c:1017 #20 0x00007ff631838b60 in main (argc=190, argv=0x3dfb0030000) at common-main.c:64 ``` The very bottom of the stack being the `rehash()` method from `hashmap.c` as called within the `name-hash` API made me look at where these hashmaps were being used in the sparse index logic. These were being copied across indexes, which seems dangerous. Indeed, clearing these hashmaps and setting them as not initialized fixes the segfault. The second commit is a response to a test failure that happens in `t1092-sparse-checkout-compatibility.sh` where `git stash pop` starts to fail because the underlying `git checkout-index` process fails due to colliding files. Passing the `-f` flag appears to work, but it's unclear why this name-hash change causes that change in behavior.
dscho
added a commit
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Mar 24, 2025
An internal customer reported a segfault when running `git sparse-checkout set` with the `index.sparse` config enabled. I was unable to reproduce it locally, but with their help we debugged into the failing process and discovered the following stacktrace: ``` #0 0x00007ff6318fb7b0 in rehash (map=0x3dfb00d0440, newsize=1048576) at hashmap.c:125 #1 0x00007ff6318fbc66 in hashmap_add (map=0x3dfb00d0440, entry=0x3dfb5c58bc8) at hashmap.c:247 #2 0x00007ff631937a70 in hash_index_entry (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:122 #3 0x00007ff631938a2f in add_name_hash (istate=0x3dfb00d0400, ce=0x3dfb5c58bc8) at name-hash.c:638 #4 0x00007ff631a064de in set_index_entry (istate=0x3dfb00d0400, nr=8291, ce=0x3dfb5c58bc8) at sparse-index.c:255 #5 0x00007ff631a06692 in add_path_to_index (oid=0x5ff130, base=0x5ff580, path=0x3dfb4b725da "<redacted>", mode=33188, context=0x5ff570) at sparse-index.c:307 #6 0x00007ff631a3b48c in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41f60, base=0x5ff580, depth=2, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:46 #7 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41e80, base=0x5ff580, depth=1, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #8 0x00007ff631a3b60b in read_tree_at (r=0x7ff631c026a0 <the_repo>, tree=0x3dfb5b41ac8, base=0x5ff580, depth=0, pathspec=0x5ff5a0, fn=0x7ff631a064e5 <add_path_to_index>, context=0x5ff570) at tree.c:80 #9 0x00007ff631a06a95 in expand_index (istate=0x3dfb00d0100, pl=0x0) at sparse-index.c:422 #10 0x00007ff631a06cbd in ensure_full_index (istate=0x3dfb00d0100) at sparse-index.c:456 #11 0x00007ff631990d08 in index_name_stage_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21, stage=0, search_mode=EXPAND_SPARSE) at read-cache.c:556 #12 0x00007ff631990d6c in index_name_pos (istate=0x3dfb00d0100, name=0x3dfb0020080 "algorithm/levenshtein", namelen=21) at read-cache.c:566 #13 0x00007ff63180dbb5 in sanitize_paths (argc=185, argv=0x3dfb0030018, prefix=0x0, skip_checks=0) at builtin/sparse-checkout.c:756 #14 0x00007ff63180de50 in sparse_checkout_set (argc=185, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:860 #15 0x00007ff63180e6c5 in cmd_sparse_checkout (argc=186, argv=0x3dfb0030018, prefix=0x0) at builtin/sparse-checkout.c:1063 #16 0x00007ff6317234cb in run_builtin (p=0x7ff631ad9b38 <commands+2808>, argc=187, argv=0x3dfb0030018) at git.c:548 #17 0x00007ff6317239c0 in handle_builtin (argc=187, argv=0x3dfb0030018) at git.c:808 #18 0x00007ff631723c7d in run_argv (argcp=0x5ffdd0, argv=0x5ffd78) at git.c:877 #19 0x00007ff6317241d1 in cmd_main (argc=187, argv=0x3dfb0030018) at git.c:1017 #20 0x00007ff631838b60 in main (argc=190, argv=0x3dfb0030000) at common-main.c:64 ``` The very bottom of the stack being the `rehash()` method from `hashmap.c` as called within the `name-hash` API made me look at where these hashmaps were being used in the sparse index logic. These were being copied across indexes, which seems dangerous. Indeed, clearing these hashmaps and setting them as not initialized fixes the segfault. The second commit is a response to a test failure that happens in `t1092-sparse-checkout-compatibility.sh` where `git stash pop` starts to fail because the underlying `git checkout-index` process fails due to colliding files. Passing the `-f` flag appears to work, but it's unclear why this name-hash change causes that change in behavior.
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v2.04b - Bot T20 CW#61 - Fix errors for CW project (Reference before punctuation)
← Previous revisionRevision as of 19:55, 8 January 2021Line 17:Line 17:
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'''Perl Compatible Regular Expressions''' ('''PCRE''') is a [[library (computing)|library]] written in [[C (programming language)|C]], which implements a [[regular expression]] engine, inspired by the capabilities of the [[Perl|Perl programming language]]. [[Philip Hazel]] started writing PCRE in summer 1997. PCRE's syntax is much more powerful and flexible than either of the [[regular expression#POSIX|POSIX regular expression]] flavors (BRE, ERE) and than that of many other regular-expression libraries.
'''Perl Compatible Regular Expressions''' ('''PCRE''') is a [[library (computing)|library]] written in [[C (programming language)|C]], which implements a [[regular expression]] engine, inspired by the capabilities of the [[Perl|Perl programming language]]. [[Philip Hazel]] started writing PCRE in summer 1997. PCRE's syntax is much more powerful and flexible than either of the [[regular expression#POSIX|POSIX regular expression]] flavors (BRE, ERE) and than that of many other regular-expression libraries.
While PCRE originally aimed at feature-equivalence with Perl, the two implementations are not fully equivalent. During the PCRE 7.x and Perl 5.9.x phase, the two projects have coordinated development, with features being ported between them in both directions.
While PCRE originally aimed at feature-equivalence with Perl, the two implementations are not fully equivalent. During the PCRE 7.x and Perl 5.9.x phase, the two projects have coordinated development, with features being ported between them in both directions.
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A number of prominent [[open-source software|open-source programs]], such as the [[Apache HTTP Server|Apache]] and [[Nginx]] HTTP servers, and the [[PHP]] and [[R (programming language)|R]] scripting languages, incorporate the PCRE library; proprietary software can do likewise, as the library is BSD-licensed. As of Perl 5.10, PCRE is also available as a replacement for Perl's default regular-expression engine through the re::engine::PCRE module.
A number of prominent [[open-source software|open-source programs]], such as the [[Apache HTTP Server|Apache]] and [[Nginx]] HTTP servers, and the [[PHP]] and [[R (programming language)|R]] scripting languages, incorporate the PCRE library; proprietary software can do likewise, as the library is BSD-licensed. As of Perl 5.10, PCRE is also available as a replacement for Perl's default regular-expression engine through the re::engine::PCRE module.
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The library can be built on Unix, Windows, and several other environments. PCRE2 is distributed with a POSIX C wrapper, several test programs, and the utility program `pcre2grep` built in tandem with the library.
The library can be built on Unix, Windows, and several other environments. PCRE2 is distributed with a POSIX C wrapper, several test programs, and the utility program `pcre2grep` built in tandem with the library.
https://en.wikipedia.org/w/index.php?title=Perl_Compatible_Regular_Expressions&diff=999160357&oldid=prev
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