diff mbox series

[bpf-next,v5,1/2] bpf: Fix uninitialized symbol in bpf_perf_link_fill_kprobe()

Message ID 20230811023647.3711-2-laoar.shao@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: Fix fill_link_info and add selftest | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1332 this patch: 1332
netdev/cc_maintainers success CCed 13 of 13 maintainers
netdev/build_clang success Errors and warnings before: 1353 this patch: 1353
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1355 this patch: 1355
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
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Commit Message

Yafang Shao Aug. 11, 2023, 2:36 a.m. UTC 
The patch 1b715e1b0ec5: "bpf: Support ->fill_link_info for
perf_event" from Jul 9, 2023, leads to the following Smatch static
checker warning:

    kernel/bpf/syscall.c:3416 bpf_perf_link_fill_kprobe()
    error: uninitialized symbol 'type'.

That can happens when uname is NULL. So fix it by verifying the uname
when we really need to fill it.

Fixes: 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/bpf/85697a7e-f897-4f74-8b43-82721bebc462@kili.mountain/
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Jiri Olsa <jolsa@kernel.org>
---
 kernel/bpf/syscall.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7f4e8c3..166390f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3378,14 +3378,14 @@  static int bpf_perf_link_fill_common(const struct perf_event *event,
 
 	if (!ulen ^ !uname)
 		return -EINVAL;
-	if (!uname)
-		return 0;
 
 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
 				      probe_offset, probe_addr);
 	if (err)
 		return err;
 
+	if (!uname)
+		return 0;
 	if (buf) {
 		len = strlen(buf);
 		err = bpf_copy_to_user(uname, buf, ulen, len);