syzbot


KMSAN: uninit-value in dvb_demux_read

Status: upstream: reported C repro on 2026/02/10 18:38
Subsystems: media
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+bd7c90de4c9f1f8ab660@syzkaller.appspotmail.com
First crash: 101d, last: 11h01m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
eb8007af-ae61-43f3-9f30-4f23fd9d746d assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ KMSAN: uninit-value in dvb_demux_read 2026/05/19 03:43 2026/05/19 03:43 2026/05/19 04:42 9f74d39908454b73546eaf1b8211b48b66e5c0fe
Discussions (4)
Title Replies (including bot) Last reply
[syzbot] Monthly media report (May 2026) 0 (1) 2026/05/02 20:32
[syzbot] Monthly media report (Apr 2026) 0 (1) 2026/04/01 13:15
[PATCH] media: dvb-core: fix uninit-value in dvb_dmxdev_read_sec 2 (2) 2026/02/21 04:32
[syzbot] [media?] KMSAN: uninit-value in dvb_demux_read 0 (2) 2026/02/11 02:22
Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/04/25 23:08 50m retest repro upstream error
2026/04/25 23:08 1h21m retest repro upstream report log
2026/04/25 23:08 53m retest repro upstream report log
2026/02/11 02:22 33m kartikey406@gmail.com patch upstream OK log

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in dvb_dmxdev_read_sec drivers/media/dvb-core/dmxdev.c:975 [inline]
BUG: KMSAN: uninit-value in dvb_demux_read+0x580/0xa40 drivers/media/dvb-core/dmxdev.c:1020
 dvb_dmxdev_read_sec drivers/media/dvb-core/dmxdev.c:975 [inline]
 dvb_demux_read+0x580/0xa40 drivers/media/dvb-core/dmxdev.c:1020
 do_loop_readv_writev fs/read_write.c:847 [inline]
 vfs_readv+0x931/0xf30 fs/read_write.c:1020
 do_preadv fs/read_write.c:1132 [inline]
 __do_sys_preadv fs/read_write.c:1179 [inline]
 __se_sys_preadv fs/read_write.c:1174 [inline]
 __x64_sys_preadv+0x2a3/0x510 fs/read_write.c:1174
 x64_sys_call+0x3033/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:296
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __alloc_frozen_pages_noprof+0x6df/0xf50 mm/page_alloc.c:5263
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2486
 alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline]
 alloc_pages_noprof+0x101/0x280 mm/mempolicy.c:2577
 vm_area_alloc_pages mm/vmalloc.c:3649 [inline]
 __vmalloc_area_node mm/vmalloc.c:3863 [inline]
 __vmalloc_node_range_noprof+0xa97/0x2d80 mm/vmalloc.c:4051
 __vmalloc_node_noprof mm/vmalloc.c:4111 [inline]
 __vmalloc_noprof+0x128/0x1f0 mm/vmalloc.c:4127
 __vmalloc_array_noprof mm/util.c:633 [inline]
 vmalloc_array_noprof+0x48/0x80 mm/util.c:644
 dvb_dmxdev_init+0xd8/0x680 drivers/media/dvb-core/dmxdev.c:1417
 vidtv_bridge_dmxdev_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:343 [inline]
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:445 [inline]
 vidtv_bridge_probe+0x1bfd/0x2690 drivers/media/test-drivers/vidtv/vidtv_bridge.c:508
 platform_probe+0x213/0x370 drivers/base/platform.c:1446
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x4d5/0xe40 drivers/base/dd.c:661
 __driver_probe_device+0x25e/0x370 drivers/base/dd.c:803
 driver_probe_device+0x70/0x8f0 drivers/base/dd.c:833
 __driver_attach+0x53e/0xaa0 drivers/base/dd.c:1227
 bus_for_each_dev+0x33b/0x580 drivers/base/bus.c:383
 driver_attach+0x51/0x70 drivers/base/dd.c:1245
 bus_add_driver+0x54f/0xdb0 drivers/base/bus.c:715
 driver_register+0x42e/0x6a0 drivers/base/driver.c:249
 __platform_driver_register+0x65/0x80 drivers/base/platform.c:908
 vidtv_bridge_init+0x73/0x100 drivers/media/test-drivers/vidtv/vidtv_bridge.c:598
 do_one_initcall+0x22b/0xad0 init/main.c:1378
 do_initcall_level+0x157/0x2e0 init/main.c:1440
 do_initcalls+0x176/0x310 init/main.c:1456
 do_basic_setup+0x1d/0x30 init/main.c:1475
 kernel_init_freeable+0x213/0x430 init/main.c:1688
 kernel_init+0x2f/0x5e0 init/main.c:1578
 ret_from_fork+0x207/0x6f0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

CPU: 1 UID: 0 PID: 6063 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
=====================================================

Crashes (147):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/07 15:30 upstream 2687c848e578 f20fc9f9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/07 13:57 upstream 2687c848e578 f20fc9f9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/07 11:12 upstream 2687c848e578 f20fc9f9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/19 01:00 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/16 18:41 upstream 6916d5703ddf a15a64a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/16 18:40 upstream 6916d5703ddf a15a64a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/16 08:11 upstream d458a240344c 81fb92f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/15 18:50 upstream 70eda68668d1 9cd3beaa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/15 02:23 upstream 66182ca873a4 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/14 11:11 upstream e1914add2799 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/13 21:03 upstream 1d5dcaa3bd65 fec2a7ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/12 04:57 upstream 50897c955902 d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/07 04:16 upstream 74fe02ce122a cbcd9ea0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/04/11 15:06 upstream e774d5f1bc27 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/04/11 14:02 upstream e774d5f1bc27 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/04/11 08:02 upstream 7c6c4ed80b87 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/04/10 01:43 upstream 8b02520ec5f7 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/04/04 06:58 upstream 631919fb12fe 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/29 03:13 upstream be762d8b6dd7 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/28 23:17 upstream be762d8b6dd7 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/28 11:08 upstream 7df48e363130 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/27 22:34 upstream 46b513250491 74a13a23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/24 08:19 upstream c369299895a5 baf8bf12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/24 08:18 upstream c369299895a5 baf8bf12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/12 15:40 upstream 80234b5ab240 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/03/02 23:19 upstream 11439c4635ed b9dd6534 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/28 01:06 upstream aed968f8a6cd 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/27 10:12 upstream a75cb869a8cc a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/25 10:50 upstream 7dff99b35460 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/22 15:40 upstream 32a92f8c8932 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/02/22 15:40 upstream 32a92f8c8932 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dvb_demux_read
2026/05/15 06:27 upstream 66182ca873a4 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/05/15 05:23 upstream 66182ca873a4 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/05/14 12:57 upstream e1914add2799 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/05/13 17:42 upstream 1d5dcaa3bd65 fec2a7ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/05/10 10:27 upstream 1bfaee9d3351 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/05/01 19:02 upstream 26fd6bff2c05 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/04/11 20:43 upstream e774d5f1bc27 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/04/10 05:49 upstream 8b02520ec5f7 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/04/04 15:37 upstream 7ca6d1cfec80 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/04/03 11:47 upstream 5619b098e2fb 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/03/24 11:55 upstream c369299895a5 baf8bf12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/03/19 01:57 upstream a989fde763f4 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/03/14 15:23 upstream 1c9982b49613 ee8d34d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/02/27 13:03 upstream a75cb869a8cc a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/02/22 17:22 upstream 32a92f8c8932 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
2026/02/20 15:14 upstream 8bf22c33e7a1 17d780d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dvb_demux_read
* Struck through repros no longer work on HEAD.