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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-06-08 14:10:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-24 17:20:11 +0300 |
| commit | df7d723d66bde3ddfd586b09d26751e72d255aba (patch) | |
| tree | bc2e1fa362e9c9f18fbef32db3dfb806ecc940c5 /tools/lib | |
| parent | 62adda4bb1b8e73b726bc431d684c5c3714c69a1 (diff) | |
| download | linux-df7d723d66bde3ddfd586b09d26751e72d255aba.tar.xz | |
tools lib api: Fix mount_overload() snprintf truncation and toupper range
[ Upstream commit fd1f70776add263f8ef38a87ae593c75303f1dcd ]
mount_overload() builds an environment variable name like
"PERF_SYSFS_ENVIRONMENT" from fs->name. Two bugs:
1) snprintf() uses name_len as the buffer size instead of sizeof(upper_name).
For fs->name = "sysfs" (len=5), the output is truncated to "PERF" (4
chars + null), so getenv() never finds the intended variable.
2) mem_toupper() only uppercases name_len bytes, converting just the "PERF"
prefix rather than the full string including the filesystem name portion.
Fix by using sizeof(upper_name) for snprintf and strlen(upper_name) for
mem_toupper, so the full "PERF_SYSFS_ENVIRONMENT" string is correctly
formatted and uppercased.
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Fixes: 73ca85ad364769ff ("tools lib api fs: Add FSTYPE__mount() method")
Cc: Jiri Olsa <jolsa@kernel.org>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/api/fs/fs.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c index d16911818d4d..cbd8eab0d1df 100644 --- a/tools/lib/api/fs/fs.c +++ b/tools/lib/api/fs/fs.c @@ -261,8 +261,8 @@ static const char *mount_overload(struct fs *fs) /* "PERF_" + name + "_ENVIRONMENT" + '\0' */ char upper_name[5 + name_len + 12 + 1]; - snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name); - mem_toupper(upper_name, name_len); + snprintf(upper_name, sizeof(upper_name), "PERF_%s_ENVIRONMENT", fs->name); + mem_toupper(upper_name, strlen(upper_name)); return getenv(upper_name) ?: *fs->mounts; } |