diff options
| author | Daniil Dulov <d.dulov@aladdin.ru> | 2026-02-13 13:01:30 +0300 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2026-02-19 15:20:41 -0500 |
| commit | f1547779402c4cd67755c33616b7203baa88420b (patch) | |
| tree | 45761ce249770cee732fdbece161579089671973 | |
| parent | 3c6e577d5ae705edebed9882ff474d7a48a47dd2 (diff) | |
ring-buffer: Fix possible dereference of uninitialized pointer
There is a pointer head_page in rb_meta_validate_events() which is not
initialized at the beginning of a function. This pointer can be dereferenced
if there is a failure during reader page validation. In this case the control
is passed to "invalid" label where the pointer is dereferenced in a loop.
To fix the issue initialize orig_head and head_page before calling
rb_validate_buffer.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://patch.msgid.link/20260213100130.2013839-1-d.dulov@aladdin.ru
Closes: https://lore.kernel.org/r/202406130130.JtTGRf7W-lkp@intel.com/
Fixes: 5f3b6e839f3c ("ring-buffer: Validate boot range memory events")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/ring_buffer.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index d33103408955..bdc8010d8f48 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1919,6 +1919,8 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) if (!meta || !meta->head_buffer) return; + orig_head = head_page = cpu_buffer->head_page; + /* Do the reader page first */ ret = rb_validate_buffer(cpu_buffer->reader_page->page, cpu_buffer->cpu); if (ret < 0) { @@ -1929,7 +1931,6 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) entry_bytes += local_read(&cpu_buffer->reader_page->page->commit); local_set(&cpu_buffer->reader_page->entries, ret); - orig_head = head_page = cpu_buffer->head_page; ts = head_page->page->time_stamp; /* |