diff options
| author | Jeongjun Park <aha310510@gmail.com> | 2025-09-05 14:18:16 +0900 |
|---|---|---|
| committer | Hans Verkuil <hverkuil+cisco@kernel.org> | 2025-10-14 15:07:37 +0200 |
| commit | 98aabfe2d79f74613abc2b0b1cef08f97eaf5322 (patch) | |
| tree | 28b3a3d1692773a6087b5ec894e0639506a7c23a | |
| parent | be440980eace19c035a0745fd6b6e42707bc4f49 (diff) | |
media: vidtv: initialize local pointers upon transfer of memory ownership
vidtv_channel_si_init() creates a temporary list (program, service, event)
and ownership of the memory itself is transferred to the PAT/SDT/EIT
tables through vidtv_psi_pat_program_assign(),
vidtv_psi_sdt_service_assign(), vidtv_psi_eit_event_assign().
The problem here is that the local pointer where the memory ownership
transfer was completed is not initialized to NULL. This causes the
vidtv_psi_pmt_create_sec_for_each_pat_entry() function to fail, and
in the flow that jumps to free_eit, the memory that was freed by
vidtv_psi_*_table_destroy() can be accessed again by
vidtv_psi_*_event_destroy() due to the uninitialized local pointer, so it
is freed once again.
Therefore, to prevent use-after-free and double-free vulnerability,
local pointers must be initialized to NULL when transferring memory
ownership.
Cc: <stable@vger.kernel.org>
Reported-by: syzbot+1d9c0edea5907af239e0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1d9c0edea5907af239e0
Fixes: 3be8037960bc ("media: vidtv: add error checks")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
| -rw-r--r-- | drivers/media/test-drivers/vidtv/vidtv_channel.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/media/test-drivers/vidtv/vidtv_channel.c b/drivers/media/test-drivers/vidtv/vidtv_channel.c index f3023e91b3eb..3541155c6fc6 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_channel.c +++ b/drivers/media/test-drivers/vidtv/vidtv_channel.c @@ -461,12 +461,15 @@ int vidtv_channel_si_init(struct vidtv_mux *m) /* assemble all programs and assign to PAT */ vidtv_psi_pat_program_assign(m->si.pat, programs); + programs = NULL; /* assemble all services and assign to SDT */ vidtv_psi_sdt_service_assign(m->si.sdt, services); + services = NULL; /* assemble all events and assign to EIT */ vidtv_psi_eit_event_assign(m->si.eit, events); + events = NULL; m->si.pmt_secs = vidtv_psi_pmt_create_sec_for_each_pat_entry(m->si.pat, m->pcr_pid); |