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| author | Sri Jayaramappa <sjayaram@akamai.com> | 2025-12-03 00:36:32 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 15:20:49 +0300 |
| commit | e9003b440603f80ad8a93f34278cca352d55d280 (patch) | |
| tree | efef7cd2317b508b90a33a95bbde764cee346d8f /tools/lib | |
| parent | 2edbcd501c7b3c29fe75ef3c3ff0c30e41d851f7 (diff) | |
| download | linux-e9003b440603f80ad8a93f34278cca352d55d280.tar.xz | |
libsubcmd: Fix null intersection case in exclude_cmds()
[ Upstream commit b6ee9b6e206b288921c14c906eebf4b32fe0c0d8 ]
When there is no exclusion occurring from the cmds list - for example -
cmds contains ["read-vdso32"] and excludes contains ["archive"] - the
main loop completes with ci == cj == 0. In the original code the loop
processing the remaining elements in the list was conditional:
if (ci != cj) { ...}
So we end up in the assertion loop since ci < cmds->cnt and we
incorrectly try to assert the list elements to be NULL and fail with
the following error
help.c:104: exclude_cmds: Assertion `cmds->names[ci] == NULL' failed.
Fix this by moving the if (ci != cj) check inside of a broader loop.
If ci != cj, left shift the list elements, as before, and then
unconditionally advance the ci and cj indicies which also covers the
ci == cj case.
Fixes: 1fdf938168c4d26f ("perf tools: Fix use-after-free in help_unknown_cmd()")
Reviewed-by: Guilherme Amadio <amadio@gentoo.org>
Signed-off-by: Sri Jayaramappa <sjayaram@akamai.com>
Tested-by: Guilherme Amadio <amadio@gentoo.org>
Tested-by: Ian Rogers <irogers@google.com>
Cc: Joshua Hunt <johunt@akamai.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20251202213632.2873731-1-sjayaram@akamai.com
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/subcmd/help.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/tools/lib/subcmd/help.c b/tools/lib/subcmd/help.c index ddaeb4eb3e24..db94aa685b73 100644 --- a/tools/lib/subcmd/help.c +++ b/tools/lib/subcmd/help.c @@ -97,11 +97,13 @@ void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes) ei++; } } - if (ci != cj) { - while (ci < cmds->cnt) { - cmds->names[cj++] = cmds->names[ci]; - cmds->names[ci++] = NULL; + while (ci < cmds->cnt) { + if (ci != cj) { + cmds->names[cj] = cmds->names[ci]; + cmds->names[ci] = NULL; } + ci++; + cj++; } for (ci = cj; ci < cmds->cnt; ci++) assert(cmds->names[ci] == NULL); |