String event fields are not necessarily NUL-terminated, so the filter
predicate functions (filter_pred_string(), filter_pred_strloc() and
filter_pred_strrelloc()) pass the field length to the regex match
callbacks, and the length-aware matchers honour it.
regex_match_glob() was the exception: it ignored the length and called
glob_match(), which scans the string until it hits a NUL byte. Some
string fields are not NUL-terminated. One example is the dynamic char
array of the xfs_* namespace tracepoints, which is copied without a
trailing NUL. For such a field, glob matching reads past the end of
the event field, causing a KASAN slab-out-of-bounds read in
glob_match(), reached via regex_match_glob() and filter_match_preds()
from the xfs_lookup tracepoint.
Add a length-bounded glob_match_len() and use it from regex_match_glob()
so glob matching always stops at the field boundary. The matching loop
is factored into a shared helper so glob_match() keeps its behaviour.
Fixes: 60f1d5e3ba ("ftrace: Support full glob matching")
Cc: [email protected]
Link: https://patch.msgid.link/da1aaf125fc3b63320b0c540fd6afa7c3d5b4f1a.1782836943.git.hhhuang@smu.edu.sg
Reported-by: Yuan Tan <[email protected]>
Reported-by: Yifan Wu <[email protected]>
Reported-by: Juefei Pu <[email protected]>
Reported-by: Zhengchuan Liang <[email protected]>
Reported-by: Xin Liu <[email protected]>
Assisted-by: Codex:GPT-5.4
Signed-off-by: Huihui Huang <[email protected]>
Signed-off-by: Ren Wei <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
back_str is only used when back_pat is non-NULL, and both are always set
together, so it is safe in practice. Initialize back_str to NULL to make
this safety invariant explicit and silence compiler/static analysis
warnings.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Josh Law <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Replace the implicit 'bool' to 'int' conversion with an explicit ternary
operator. This makes the pointer arithmetic clearer and avoids relying on
boolean memory representation for logic flow.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Josh Law <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Fix a missing article ('a') in the comment describing the glob
implementation, and replace 'blacklists' with 'denylists' to align with
the kernel's inclusive terminology guidelines.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Josh Law <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Add null check for character class. Previously, an inverted character
class could result in a nul byte being matched and lead to the function
reading past the end of the inputted string.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alok Swaminathan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Clang static analysis reports this false positive
glob.c:48:32: warning: Assigned value is garbage
or undefined
char const *back_pat = NULL, *back_str = back_str;
^~~~~~~~ ~~~~~~~~
back_str is set after back_pat and it's use is protected by the !back_pat
check. It is not necessary to initialize back_str, so remove the
initialization.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Tom Rix <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
The following build error for powerpc64 was reported by Nathan Chancellor:
"$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ
$ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage
...
In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234,
from arch/powerpc/boot/decompress.c:38:
arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main':
arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function)
586 | fallthrough;
| ^~~~~~~~~~~
This will end up affecting distribution configurations such as Debian
and OpenSUSE according to my testing. I am not sure what the solution
is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure
that compiler_attributes.h can be safely included."
In order to avoid these sort of problems, it seems that the best
solution is to use /* fall through */ comments instead of the
fallthrough pseudo-keyword macro in lib/, for now.
Reported-by: Nathan Chancellor <[email protected]>
Fixes: df561f6688 ("treewide: Use fallthrough pseudo-keyword")
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Reviewed-and-tested-by: Nathan Chancellor <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This was useful during development, and is retained for future
regression testing.
GCC appears to have no way to place string literals in a particular
section; adding __initconst to a char pointer leaves the string itself
in the default string section, where it will not be thrown away after
module load.
Thus all string constants are kept in explicitly declared and named
arrays. Sorry this makes printk a bit harder to read. At least the
tests are more compact.
Signed-off-by: George Spelvin <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This is a helper function from drivers/ata/libata_core.c, where it is
used to blacklist particular device models. It's being moved to lib/ so
other drivers may use it for the same purpose.
This implementation in non-recursive, so is safe for the kernel stack.
[[email protected]: fix sparse warning]
Signed-off-by: George Spelvin <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Huihui Huang