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KASAN: use-after-free Read in dvb_device_open

Status: upstream: reported C repro on 2026/02/08 16:16
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+77c81ec5baefe5b53fd2@syzkaller.appspotmail.com
First crash: 138d, last: now
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/02/21 linux-5.15.y (ToT) 3330a8d33e08 C [report] KASAN: use-after-free Read in dvb_device_open
2026/02/21 upstream (ToT) d79526b89571 C Didn't crash
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in dvb_device_open origin:upstream 19 C 713 48m 139d 0/3 upstream: reported C repro on 2026/02/07 10:59
upstream KASAN: slab-use-after-free Read in dvb_device_open prio:normal media 22 C error 11345 now 552d 0/29 upstream: reported C repro on 2024/12/21 08:54
linux-6.6 KFENCE: use-after-free read in dvb_device_open origin:upstream 22 C 395 40m 138d 0/2 upstream: reported C repro on 2026/02/08 23:24
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2026/03/23 21:46 1m fix candidate upstream error job log
2026/02/21 16:18 1m fix candidate upstream error job log

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in dvb_device_open+0xc5/0x360 drivers/media/dvb-core/dvbdev.c:109
Read of size 8 at addr ffff888027f5cc18 by task syz.0.38/4450

CPU: 1 PID: 4450 Comm: syz.0.38 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 dvb_device_open+0xc5/0x360 drivers/media/dvb-core/dvbdev.c:109
 chrdev_open+0x585/0x5f0 fs/char_dev.c:414
 do_dentry_open+0x7f7/0xf90 fs/open.c:826
 do_open fs/namei.c:3616 [inline]
 path_openat+0x2718/0x2fb0 fs/namei.c:3750
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f74e4f7268e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f74e45f1b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f74e45f26c0 RCX: 00007f74e4f7268e
RDX: 0000000000000002 RSI: 00007f74e45f1c00 RDI: ffffffffffffff9c
RBP: 00007f74e45f1c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f74e522b128 R14: 00007f74e522b090 R15: 00007ffcbf49f0b8
 </TASK>

Allocated by task 1:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 dvb_register_device+0x300/0x1dc0 drivers/media/dvb-core/dvbdev.c:488
 dvb_register_frontend+0x629/0x900 drivers/media/dvb-core/dvb_frontend.c:3034
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
 vidtv_bridge_probe+0x9c1/0xf30 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x276/0xc70 drivers/base/dd.c:595
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
 __driver_attach+0x45d/0x660 drivers/base/dd.c:1184
 bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303
 bus_add_driver+0x324/0x5d0 drivers/base/bus.c:620
 driver_register+0x32d/0x430 drivers/base/driver.c:240
 vidtv_bridge_init+0x39/0x70 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
 do_one_initcall+0x272/0x730 init/main.c:1315
 do_initcall_level+0x13d/0x1f0 init/main.c:1388
 do_initcalls+0x4b/0x90 init/main.c:1404
 kernel_init_freeable+0x3d5/0x560 init/main.c:1628
 kernel_init+0x19/0x1b0 init/main.c:1519
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Freed by task 4447:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 dvb_free_device drivers/media/dvb-core/dvbdev.c:635 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put drivers/media/dvb-core/dvbdev.c:650 [inline]
 dvb_device_open+0x2d2/0x360 drivers/media/dvb-core/dvbdev.c:123
 chrdev_open+0x585/0x5f0 fs/char_dev.c:414
 do_dentry_open+0x7f7/0xf90 fs/open.c:826
 do_open fs/namei.c:3616 [inline]
 path_openat+0x2718/0x2fb0 fs/namei.c:3750
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888027f5cc00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 24 bytes inside of
 256-byte region [ffff888027f5cc00, ffff888027f5cd00)
The buggy address belongs to the page:
page:ffffea00009fd700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27f5c
head:ffffea00009fd700 order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000200000001 ffff888016c41b40
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2836, ts 21107869426, free_ts 0
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 set_kthread_struct kernel/kthread.c:103 [inline]
 kthread+0x10a/0x520 kernel/kthread.c:296
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888027f5cb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888027f5cb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888027f5cc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888027f5cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888027f5cd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (334):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/26 15:15 linux-5.15.y eceeec79dbc6 7ff32d8b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/26 10:06 linux-5.15.y eceeec79dbc6 7ff32d8b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/18 02:37 linux-5.15.y dc027a595035 b62b3ded .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/02/21 14:44 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/27 04:48 linux-5.15.y eceeec79dbc6 fb92f11c .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/26 12:30 linux-5.15.y eceeec79dbc6 7ff32d8b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/19 00:21 linux-5.15.y dc027a595035 a776b0d0 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/06 10:32 linux-5.15.y dc027a595035 cc095639 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/02/09 04:38 linux-5.15.y 7b232985052f 4c131dc4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/27 01:57 linux-5.15.y eceeec79dbc6 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/26 06:48 linux-5.15.y eceeec79dbc6 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/26 06:47 linux-5.15.y eceeec79dbc6 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/25 17:00 linux-5.15.y eceeec79dbc6 cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/25 03:34 linux-5.15.y eceeec79dbc6 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/25 03:29 linux-5.15.y eceeec79dbc6 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/23 16:32 linux-5.15.y eceeec79dbc6 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/23 15:10 linux-5.15.y eceeec79dbc6 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/22 05:39 linux-5.15.y eceeec79dbc6 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/19 16:52 linux-5.15.y eceeec79dbc6 570c59ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/18 00:01 linux-5.15.y dc027a595035 b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/17 23:42 linux-5.15.y dc027a595035 b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/16 02:02 linux-5.15.y dc027a595035 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/15 21:43 linux-5.15.y dc027a595035 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/15 21:27 linux-5.15.y dc027a595035 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/13 23:24 linux-5.15.y dc027a595035 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/12 13:45 linux-5.15.y dc027a595035 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/12 13:44 linux-5.15.y dc027a595035 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/12 11:14 linux-5.15.y dc027a595035 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/11 05:32 linux-5.15.y dc027a595035 b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/11 04:29 linux-5.15.y dc027a595035 b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/10 23:26 linux-5.15.y dc027a595035 f79bac11 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/10 17:15 linux-5.15.y dc027a595035 f79bac11 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/09 09:34 linux-5.15.y dc027a595035 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/09 03:15 linux-5.15.y dc027a595035 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/07 12:02 linux-5.15.y dc027a595035 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/06 08:33 linux-5.15.y dc027a595035 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/06 06:05 linux-5.15.y dc027a595035 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/06/02 21:15 linux-5.15.y dc027a595035 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/28 22:19 linux-5.15.y 241d66fa280c 681715f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/28 21:18 linux-5.15.y 241d66fa280c 681715f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/28 16:12 linux-5.15.y 241d66fa280c 681715f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/26 11:35 linux-5.15.y 241d66fa280c a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/26 03:51 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/26 03:40 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/25 14:03 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/24 07:40 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/20 13:21 linux-5.15.y 93741761e5e3 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/18 16:50 linux-5.15.y 93741761e5e3 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/17 09:07 linux-5.15.y 93741761e5e3 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/17 09:06 linux-5.15.y 93741761e5e3 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/17 04:37 linux-5.15.y 93741761e5e3 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/05/16 19:10 linux-5.15.y 93741761e5e3 a15a64a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
2026/02/08 16:15 linux-5.15.y 7b232985052f 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in dvb_device_open
* Struck through repros no longer work on HEAD.