CVE-2026-53382

In the Linux kernel, the following vulnerability has been resolved:

media: vidtv: fix NULL pointer dereference in vidtvmuxpush_si

syzbot reported a general protection fault in vidtvpsitspsiwrite_into [1].

vidtvmuxgetpidctx() can return NULL, but vidtvmuxpush_si() does not check for this before dereferencing the returned pointer to access the continuity counter. This leads to a general protection fault when accessing a near-NULL address.

The root cause is that vidtvmuxpidctxinit() does not check the return value of vidtvmuxcreatepidctxonce() for PMT section PIDs. If the allocation fails, the PID context is never created, but init returns success. The subsequent vidtvmuxpushsi() call then gets NULL from vidtvmuxgetpidctx() and crashes.

Fix both the root cause (add error check in vidtvmuxpidctxinit for PMT PIDs) and add defensive NULL checks in vidtvmuxpushsi for all vidtvmuxgetpid_ctx() calls.

[1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] Workqueue: events vidtvmuxtick RIP: 0010:vidtvpsitspsiwriteinto+0x54a/0xbc0 drivers/media/test-drivers/vidtv/vidtvpsi.c:197 Call Trace: <TASK> vidtvpsitableheaderwriteinto drivers/media/test-drivers/vidtv/vidtvpsi.c:799 [inline] vidtvpsipmtwriteinto+0x3b2/0xa70 drivers/media/test-drivers/vidtv/vidtvpsi.c:1231 vidtvmuxpushsi+0x932/0xe80 drivers/media/test-drivers/vidtv/vidtvmux.c:196 vidtvmuxtick+0xe9b/0x1480 drivers/media/test-drivers/vidtv/vidtvmux.c:408