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

Status: auto-obsoleted due to no activity on 2025/11/15 19:20
Subsystems: modules
[Documentation on labels]
Reported-by: syzbot+0f50913bb9389d880a66@syzkaller.appspotmail.com
First crash: 333d, last: 205d
▶ ▼ 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 21 8 4d21h 28d 0/3 upstream: reported on 2026/02/11 05:44
linux-5.15 KASAN: slab-out-of-bounds Write in try_module_get 21 2 8d13h 8d13h 0/3 upstream: reported on 2026/03/02 19:08
android-5-10 KASAN: slab-out-of-bounds Write in try_module_get 21 11 240d 311d 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 (2) modules 22 78 5h58m 32d 0/29 upstream: reported on 2026/02/06 18:05
linux-6.6 KASAN: slab-out-of-bounds Write in try_module_get 21 1 8d00h 8d00h 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:96 [inline]
BUG: KASAN: slab-out-of-bounds in atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1536 [inline]
BUG: KASAN: slab-out-of-bounds in try_module_get+0x4c/0xd0 kernel/module/main.c:859
Write of size 4 at addr ffff8881416a9cf8 by task syz.1.357/7939

CPU: 1 UID: 0 PID: 7939 Comm: syz.1.357 Tainted: G     U              6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1536 [inline]
 try_module_get+0x4c/0xd0 kernel/module/main.c:859
 dvb_device_open+0x124/0x3b0 drivers/media/dvb-core/dvbdev.c:103
 chrdev_open+0x231/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x741/0x1c10 fs/open.c:956
 vfs_open+0x82/0x3f0 fs/open.c:1086
 do_open fs/namei.c:3880 [inline]
 path_openat+0x1e5e/0x2d40 fs/namei.c:4039
 do_filp_open+0x20b/0x470 fs/namei.c:4066
 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x174/0x210 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f48aed8e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f48afbdb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f48aefb5fa0 RCX: 00007f48aed8e969
RDX: 0000000000000040 RSI: 0000200000000580 RDI: ffffffffffffff9c
RBP: 00007f48aee10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f48aefb5fa0 R15: 00007ffee6f25cf8
 </TASK>

Allocated by task 1:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 dvb_register_device+0x1e4/0x2370 drivers/media/dvb-core/dvbdev.c:475
 dvb_dmxdev_init+0x33e/0x4e0 drivers/media/dvb-core/dmxdev.c:1435
 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+0x75d/0xa90 drivers/media/test-drivers/vidtv/vidtv_bridge.c:508
 platform_probe+0xff/0x1f0 drivers/base/platform.c:1404
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x241/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __driver_attach+0x283/0x580 drivers/base/dd.c:1215
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:370
 bus_add_driver+0x2e9/0x690 drivers/base/bus.c:678
 driver_register+0x15c/0x4b0 drivers/base/driver.c:249
 vidtv_bridge_init+0x45/0x80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:598
 do_one_initcall+0x120/0x6e0 init/main.c:1257
 do_initcall_level init/main.c:1319 [inline]
 do_initcalls init/main.c:1335 [inline]
 do_basic_setup init/main.c:1354 [inline]
 kernel_init_freeable+0x5c2/0x900 init/main.c:1567
 kernel_init+0x1c/0x2b0 init/main.c:1457
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8881416a9c00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 32 bytes to the right of
 allocated 216-byte region [ffff8881416a9c00, ffff8881416a9cd8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1416a8
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801b441b40 ffffea00015f2c80 0000000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801b441b40 ffffea00015f2c80 0000000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000001 ffffea000505aa01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
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, tgid 1 (swapper/0), ts 23366561951, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688
 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab mm/slub.c:2618 [inline]
 new_slab+0x244/0x340 mm/slub.c:2672
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4353
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 bus_add_driver+0x92/0x690 drivers/base/bus.c:662
 driver_register+0x15c/0x4b0 drivers/base/driver.c:249
 usb_register_driver+0x216/0x4d0 drivers/usb/core/driver.c:1078
 do_one_initcall+0x120/0x6e0 init/main.c:1257
 do_initcall_level init/main.c:1319 [inline]
 do_initcalls init/main.c:1335 [inline]
 do_basic_setup init/main.c:1354 [inline]
 kernel_init_freeable+0x5c2/0x900 init/main.c:1567
 kernel_init+0x1c/0x2b0 init/main.c:1457
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881416a9b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881416a9c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881416a9c80: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
                                                                ^
 ffff8881416a9d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881416a9d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/16 15:52 upstream fee3e843b309 cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-out-of-bounds Write in try_module_get
2025/04/11 15:14 upstream 900241a5cc15 12ba9c21 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-out-of-bounds Write in try_module_get
2025/08/17 19:19 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto general protection fault in try_module_get
2025/07/11 05:01 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto general protection fault in try_module_get
* Struck through repros no longer work on HEAD.