KASAN: slab-out-of-bounds Write in try_module_get

Status: upstream: reported on 2026/03/02 19:08
Reported-by: syzbot+16d5985fa5c27b7d23f4@syzkaller.appspotmail.com
First crash: 152d, last: 37d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: slab-out-of-bounds Write in try_module_get 22 25 5d17h 171d 0/3 upstream: reported on 2026/02/11 05:44
android-5-10 KASAN: slab-out-of-bounds Write in try_module_get 21 11 383d 455d 0/2 auto-obsoleted due to no activity on 2025/10/12 05:38
upstream KASAN: slab-out-of-bounds Write in try_module_get modules 21 4 349d 473d 0/29 auto-obsoleted due to no activity on 2025/11/15 19:20
upstream KASAN: slab-out-of-bounds Write in try_module_get (2) prio:high modules 22 352 6h12m 176d 0/29 upstream: reported on 2026/02/06 18:05
linux-6.6 KASAN: slab-out-of-bounds Write in try_module_get 21 3 40d 151d 0/2 upstream: reported on 2026/03/03 08:42

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: slab-out-of-bounds in atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:577 [inline]
BUG: KASAN: slab-out-of-bounds in try_module_get+0x4f/0xf0 kernel/module.c:1077
Write of size 4 at addr ffff8880299e51a0 by task syz.5.1023/8510

CPU: 0 PID: 8510 Comm: syz.5.1023 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
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:577 [inline]
 try_module_get+0x4f/0xf0 kernel/module.c:1077
 dvb_device_open+0xf0/0x360 drivers/media/dvb-core/dvbdev.c:113
 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: 0033:0x7f07f487668e
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:00007f07f2b0eb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f07f2b0f6c0 RCX: 00007f07f487668e
RDX: 0000000000000002 RSI: 00007f07f2b0ec00 RDI: ffffffffffffff9c
RBP: 00007f07f2b0ec00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f07f4b2f038 R14: 00007f07f4b2efa0 R15: 00007ffd6502f118
 </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_dmxdev_init+0x2bf/0x410 drivers/media/dvb-core/dmxdev.c:1442
 vidtv_bridge_dmxdev_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:345 [inline]
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:447 [inline]
 vidtv_bridge_probe+0xb7b/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

The buggy address belongs to the object at ffff8880299e5000
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 160 bytes to the right of
 256-byte region [ffff8880299e5000, ffff8880299e5100)
The buggy address belongs to the page:
page:ffffea0000a67900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x299e4
head:ffffea0000a67900 order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000180f680 0000000c00000007 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 1, ts 18383734383, 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_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
 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]
 __kmalloc_node+0x142/0x3a0 mm/slub.c:4456
 kmalloc_node include/linux/slab.h:630 [inline]
 kvmalloc_node+0x84/0x130 mm/util.c:619
 kvmalloc include/linux/mm.h:816 [inline]
 kvzalloc include/linux/mm.h:824 [inline]
 v4l2_ctrl_new+0x70f/0x1310 drivers/media/v4l2-core/v4l2-ctrls-core.c:1306
 v4l2_ctrl_new_std+0x247/0x300 drivers/media/v4l2-core/v4l2-ctrls-core.c:1429
 handler_new_ref+0x14f/0x8d0 drivers/media/v4l2-core/v4l2-ctrls-core.c:1098
 v4l2_ctrl_add_handler+0x197/0x280 drivers/media/v4l2-core/v4l2-ctrls-core.c:1573
 vivid_create_controls+0x27b0/0x3380 drivers/media/test-drivers/vivid/vivid-ctrls.c:1907
 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1860 [inline]
 vivid_probe+0x39ff/0x6240 drivers/media/test-drivers/vivid/vivid-core.c:2031
 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
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880299e5080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
 ffff8880299e5100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880299e5180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8880299e5200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880299e5280: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/25 03:48 linux-5.15.y eceeec79dbc6 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/06/23 15:56 linux-5.15.y eceeec79dbc6 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/06/18 13:50 linux-5.15.y dc027a595035 a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/06/09 09:38 linux-5.15.y dc027a595035 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/06/06 08:36 linux-5.15.y dc027a595035 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/05/26 03:41 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/05/11 18:05 linux-5.15.y de8dfb3f0278 845acb1c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/04/10 01:02 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/03/02 19:10 linux-5.15.y 3330a8d33e08 b9dd6534 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/03/02 19:07 linux-5.15.y 3330a8d33e08 b9dd6534 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in try_module_get
2026/06/17 23:59 linux-5.15.y dc027a595035 b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in try_module_get
2026/05/26 04:06 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in try_module_get
* Struck through repros no longer work on HEAD.