================================================================== BUG: KASAN: slab-use-after-free in v4l2_open+0x342/0x360 drivers/media/v4l2-core/v4l2-dev.c:432 Read of size 4 at addr ffff888024454800 by task v4l_id/5646 CPU: 1 PID: 5646 Comm: v4l_id Not tainted 6.8.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b5/0x2a0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x163/0x510 mm/kasan/report.c:488 kasan_report+0xcd/0x100 mm/kasan/report.c:601 v4l2_open+0x342/0x360 drivers/media/v4l2-core/v4l2-dev.c:432 chrdev_open+0x50f/0x5d0 fs/char_dev.c:414 do_dentry_open+0x8fd/0x1590 fs/open.c:953 path_openat+0x280d/0x31d0 fs/namei.c:3645 do_filp_open+0x26d/0x500 fs/namei.c:3829 do_sys_openat2+0x12f/0x1c0 fs/open.c:1404 do_sys_open fs/open.c:1419 [inline] __do_sys_openat fs/open.c:1435 [inline] __se_sys_openat fs/open.c:1430 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1430 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f3dabb169a4 Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffc466ecd40 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc466ecf58 RCX: 00007f3dabb169a4 RDX: 0000000000000000 RSI: 00007ffc466edf1e RDI: 00000000ffffff9c RBP: 00007ffc466edf1e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc466ecf70 R14: 0000555aa0ec0670 R15: 00007f3dac0aca80 Allocated by task 8: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x60 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1e6/0x400 mm/slub.c:4012 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] em28xx_v4l2_init+0x107/0x2dc0 drivers/media/usb/em28xx/em28xx-video.c:2539 em28xx_init_extension+0x11f/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116 process_scheduled_works+0x96f/0x1490 kernel/workqueue.c:2633 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2787 kthread+0x2cd/0x360 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243 Freed by task 8: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x60 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:589 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x14a/0x370 mm/slub.c:4409 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x1608/0x2dc0 drivers/media/usb/em28xx/em28xx-video.c:2908 em28xx_init_extension+0x11f/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116 process_scheduled_works+0x96f/0x1490 kernel/workqueue.c:2633 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2787 kthread+0x2cd/0x360 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243 The buggy address belongs to the object at ffff888024454000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2048 bytes inside of freed 8192-byte region [ffff888024454000, ffff888024456000) The buggy address belongs to the physical page: page:ffffea0000911400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24450 head:ffffea0000911400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888011442280 ffffea0001ede600 0000000000000005 raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4658, tgid 4658 (S41dhcpcd), ts 32416679882, free_ts 32403418572 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x3355/0x34e0 mm/page_alloc.c:3311 __alloc_pages+0x255/0x670 mm/page_alloc.c:4567 alloc_slab_page+0x5f/0x150 include/linux/gfp.h:238 new_slab+0x84/0x2f0 mm/slub.c:2354 ___slab_alloc+0xc77/0x1310 mm/slub.c:3540 kmalloc_trace+0x276/0x400 mm/slub.c:3625 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0x1228/0x2130 security/tomoyo/audit.c:264 tomoyo_supervisor+0x37a/0x1370 security/tomoyo/common.c:2089 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x157/0x1f0 security/tomoyo/environ.c:63 tomoyo_find_next_domain+0x139a/0x1d40 security/tomoyo/domain.c:672 tomoyo_bprm_check_security+0x114/0x170 security/tomoyo/tomoyo.c:102 security_bprm_check+0x63/0xa0 security/security.c:1188 bprm_execve+0xa45/0x1840 fs/exec.c:1771 do_execveat_common+0x552/0x6f0 fs/exec.c:1984 do_execve fs/exec.c:2058 [inline] __do_sys_execve fs/exec.c:2134 [inline] __se_sys_execve fs/exec.c:2129 [inline] __x64_sys_execve+0x92/0xa0 fs/exec.c:2129 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83 page last free pid 4657 tgid 4657 stack trace: free_unref_page_prepare+0x94d/0xa60 include/linux/page_owner.h:24 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 __put_partials+0xeb/0x130 mm/slub.c:2453 put_cpu_partial+0x169/0x240 mm/slub.c:2997 __slab_free+0x2c3/0x400 mm/slub.c:4166 qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:163 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] __do_kmalloc_node mm/slub.c:3980 [inline] __kmalloc+0x1dd/0x540 mm/slub.c:3994 kmalloc include/linux/slab.h:594 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_path_perm+0x24d/0x5b0 security/tomoyo/file.c:151 security_inode_getattr+0xd3/0x120 security/security.c:2238 vfs_fstatat+0xca/0x1b0 fs/stat.c:173 __se_sys_newfstatat fs/stat.c:468 [inline] __x64_sys_newfstatat+0xff/0x170 fs/stat.c:462 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Memory state around the buggy address: ffff888024454700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024454780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888024454800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888024454880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024454900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================