hexdump-parse: handle truncated format pattern #2133
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
If the fmt being parsed by block_size is exactly '%', *++fmt is the
terminator and strchr will return a valid pointer to the terminator of
spec rather than NULL, the while condition will pass and subsequent
strchr will read past the end of fmt until a spec character is found
again
ASAN aborts with the following error on the first buffer overread:
AddressSanitizer: heap-buffer-overflow on address 0x602000000212 at pc 0x55bf1c4b2d78 bp 0x7ffe33c8cff0 sp 0x7ffe33c8cfe0
READ of size 1 at 0x602000000212 thread T0
#0 0x55bf1c4b2d77 in block_size ../text-utils/hexdump-parse.c:207
util-linux#1 0x55bf1c4ad36f in main ../text-utils/hexdump.c:214
util-linux#2 0x7f15f063c78f (/usr/lib/libc.so.6+0x2378f)
util-linux#3 0x7f15f063c849 in __libc_start_main (/usr/lib/libc.so.6+0x23849)
util-linux#4 0x55bf1c4ac6c4 in _start (../build/hexdump+0x86c4)
|
Noticed that next_number also increments fmt, so we need to move the null check below that too. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
If the fmt being parsed by block_size is exactly '%', *++fmt is the terminator and strchr will return a valid pointer to the terminator of spec rather than NULL, the while condition will pass and subsequent strchr will read past the end of fmt until a spec character is found again
ASAN aborts with the following error on the first buffer overread: