================================================================== BUG: KASAN: slab-use-after-free in v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 Read of size 8 at addr ffff88811173c738 by task v4l_id/3156 CPU: 1 UID: 0 PID: 3156 Comm: v4l_id Not tainted 6.11.0-rc4-syzkaller-00047-gca7df2c7bb5f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 v4l2_fh_open+0x89/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x250/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2155 v4l2_open+0x228/0x490 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x26d/0x6f0 fs/char_dev.c:414 do_dentry_open+0x957/0x1490 fs/open.c:959 vfs_open+0x82/0x3f0 fs/open.c:1089 do_open fs/namei.c:3727 [inline] path_openat+0x2141/0x2d20 fs/namei.c:3886 do_filp_open+0x1dc/0x430 fs/namei.c:3913 do_sys_openat2+0x17a/0x1e0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1442 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f07bdb519a4 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:00007ffc73c03e00 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc73c04018 RCX: 00007f07bdb519a4 RDX: 0000000000000000 RSI: 00007ffc73c05f26 RDI: 00000000ffffff9c RBP: 00007ffc73c05f26 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc73c04030 R14: 000055c3948f3670 R15: 00007f07bdfa0a80 Allocated by task 8: 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:370 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:681 [inline] kzalloc_noprof include/linux/slab.h:807 [inline] em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2534 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 8: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x10b/0x380 mm/slub.c:4594 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x22a4/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2903 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff88811173c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1848 bytes inside of freed 8192-byte region [ffff88811173c000, ffff88811173e000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111738 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: 0xfdffffff(slab) raw: 0200000000000040 ffff888100042280 ffffea00043ebc00 0000000000000002 raw: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000 head: 0200000000000040 ffff888100042280 ffffea00043ebc00 0000000000000002 head: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000 head: 0200000000000003 ffffea000445ce01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 2605, tgid 2605 (getty), ts 16532817953, free_ts 16407322269 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3439 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x4e/0xf0 mm/slub.c:2321 allocate_slab mm/slub.c:2484 [inline] new_slab+0x84/0x260 mm/slub.c:2537 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __kmalloc_cache_noprof+0x27a/0x2c0 mm/slub.c:4184 kmalloc_noprof include/linux/slab.h:681 [inline] audit_log_d_path+0xce/0x1e0 kernel/audit.c:2148 dump_common_audit_data security/lsm_audit.c:237 [inline] common_lsm_audit+0x3d3/0x2220 security/lsm_audit.c:458 slow_avc_audit+0x17d/0x210 security/selinux/avc.c:781 avc_audit security/selinux/include/avc.h:127 [inline] avc_has_perm+0x18d/0x1c0 security/selinux/avc.c:1199 inode_has_perm+0x168/0x1d0 security/selinux/hooks.c:1671 file_path_has_perm security/selinux/hooks.c:1715 [inline] selinux_file_open+0x329/0x440 security/selinux/hooks.c:3997 security_file_open+0x65/0xb0 security/security.c:2988 do_dentry_open+0x5fa/0x1490 fs/open.c:946 page last free pid 2602 tgid 2602 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0x698/0xce0 mm/page_alloc.c:2612 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_noprof+0x11c/0x2b0 mm/slub.c:4044 getname_flags.part.0+0x4c/0x550 fs/namei.c:139 getname_flags+0x93/0xf0 include/linux/audit.h:322 vfs_fstatat+0x86/0x160 fs/stat.c:340 __do_sys_newfstatat+0xa2/0x130 fs/stat.c:505 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88811173c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811173c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811173c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811173c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811173c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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