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| author | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2022-01-13 11:28:36 +0530 |
|---|---|---|
| committer | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2022-01-24 11:36:19 +0530 |
| commit | f7a79879c0b2bef0dadd6caaaeeb0d26423e04e5 (patch) | |
| tree | 724aa1baeb79a46759b00e38bbff40efb7845f61 /stdlib/canonicalize.c | |
| parent | 73c362840c4efde45125a6c27bf41726397f4038 (diff) | |
| download | glibc-f7a79879c0b2bef0dadd6caaaeeb0d26423e04e5.tar.xz glibc-f7a79879c0b2bef0dadd6caaaeeb0d26423e04e5.zip | |
realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770]
realpath returns an allocated string when the result exceeds PATH_MAX,
which is unexpected when its second argument is not NULL. This results
in the second argument (resolved) being uninitialized and also results
in a memory leak since the caller expects resolved to be the same as the
returned value.
Return NULL and set errno to ENAMETOOLONG if the result exceeds
PATH_MAX. This fixes [BZ #28770], which is CVE-2021-3998.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit ee8d5e33adb284601c00c94687bc907e10aec9bb)
Diffstat (limited to 'stdlib/canonicalize.c')
| -rw-r--r-- | stdlib/canonicalize.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/stdlib/canonicalize.c b/stdlib/canonicalize.c index 698f9ede25..7a23a51b3a 100644 --- a/stdlib/canonicalize.c +++ b/stdlib/canonicalize.c @@ -400,8 +400,16 @@ realpath_stk (const char *name, char *resolved, error: *dest++ = '\0'; - if (resolved != NULL && dest - rname <= get_path_max ()) - rname = strcpy (resolved, rname); + if (resolved != NULL) + { + if (dest - rname <= get_path_max ()) + rname = strcpy (resolved, rname); + else + { + failed = true; + __set_errno (ENAMETOOLONG); + } + } error_nomem: scratch_buffer_free (&extra_buffer); |