================================================================== BUG: KASAN: slab-use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] BUG: KASAN: slab-use-after-free in v4l2_fh_open+0xc8/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff88804fdc0738 by task v4l_id/15044 CPU: 1 UID: 0 PID: 15044 Comm: v4l_id Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xc8/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x14c/0x9d0 drivers/media/usb/em28xx/em28xx-video.c:2153 v4l2_open+0x22f/0x370 drivers/media/v4l2-core/v4l2-dev.c:429 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0x978/0x1460 fs/open.c:941 vfs_open+0x3e/0x330 fs/open.c:1071 do_open fs/namei.c:3828 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1398 do_sys_open fs/open.c:1413 [inline] __do_sys_openat fs/open.c:1429 [inline] __se_sys_openat fs/open.c:1424 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1424 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f28b5b169a4 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:00007ffe96fb8020 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffe96fb8238 RCX: 00007f28b5b169a4 RDX: 0000000000000000 RSI: 00007ffe96fb8f1b RDI: 00000000ffffff9c RBP: 00007ffe96fb8f1b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe96fb8250 R14: 000056212e253670 R15: 00007f28b60fca80 Allocated by task 5897: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:257 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:879 [inline] kzalloc_noprof include/linux/slab.h:1015 [inline] em28xx_v4l2_init+0xfd/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 5897: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x1a0/0x440 mm/slub.c:4727 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x16d7/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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 ffff88804fdc0000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1848 bytes inside of freed 8192-byte region [ffff88804fdc0000, ffff88804fdc2000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4fdc0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac42280 ffffea0000c0a800 0000000000000003 raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801ac42280 ffffea0000c0a800 0000000000000003 head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea00013f7001 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5516, tgid 5516 (dhcpcd), ts 267864214734, free_ts 267834797029 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3474 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2412 allocate_slab+0x5a/0x2f0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818 __slab_alloc+0x58/0xa0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __do_kmalloc_node mm/slub.c:4263 [inline] __kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4283 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] netlink_dump+0x1ee/0xe10 net/netlink/af_netlink.c:2282 netlink_recvmsg+0x6bb/0x11d0 net/netlink/af_netlink.c:1973 sock_recvmsg_nosec net/socket.c:1033 [inline] sock_recvmsg+0x22f/0x280 net/socket.c:1055 ____sys_recvmsg+0x1c6/0x480 net/socket.c:2803 ___sys_recvmsg net/socket.c:2845 [inline] __sys_recvmsg+0x291/0x390 net/socket.c:2878 page last free pid 14454 tgid 14454 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657 __folio_put+0x2c7/0x440 mm/swap.c:112 skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x483/0x8a0 net/core/skbuff.c:1119 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242 kfree_skb_reason include/linux/skbuff.h:1263 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3343 [inline] __skb_queue_purge include/linux/skbuff.h:3348 [inline] mptcp_destroy_common+0x428/0x600 net/mptcp/protocol.c:3408 mptcp_destroy+0x86/0x120 net/mptcp/protocol.c:3428 __mptcp_destroy_sock+0x154/0x400 net/mptcp/protocol.c:3050 __mptcp_close+0x7c8/0xb60 net/mptcp/protocol.c:3153 mptcp_close+0x2a/0x1a0 net/mptcp/protocol.c:3168 inet_release+0x17d/0x200 net/ipv4/af_inet.c:435 __sock_release net/socket.c:640 [inline] sock_close+0xbc/0x240 net/socket.c:1408 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88804fdc0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804fdc0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804fdc0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804fdc0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804fdc0800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================