================================================================== 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 ffff88802d028740 by task v4l_id/5592 CPU: 0 PID: 5592 Comm: v4l_id Not tainted 6.10.0-syzkaller-10894-g8326f5e1a47b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 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+0x91f/0x15f0 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: 0033:0x7fc5af5739a4 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:00007fff9d4e35a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fff9d4e37b8 RCX: 00007fc5af5739a4 RDX: 0000000000000000 RSI: 00007fff9d4e4f20 RDI: 00000000ffffff9c RBP: 00007fff9d4e4f20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff9d4e37d0 R14: 000056416487b670 R15: 00007fc5af734a80 Allocated by task 25: 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+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:681 [inline] kzalloc_noprof include/linux/slab.h:807 [inline] em28xx_v4l2_init+0x114/0x4070 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 25: 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+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2235 [inline] slab_free mm/slub.c:4464 [inline] kfree+0x12a/0x3b0 mm/slub.c:4585 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x22a9/0x4070 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 ffff88802d028000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1856 bytes inside of freed 8192-byte region [ffff88802d028000, ffff88802d02a000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2d028 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 00fff00000000040 ffff888015442280 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080020002 00000001ffffefff 0000000000000000 head: 00fff00000000040 ffff888015442280 0000000000000000 dead000000000001 head: 0000000000000000 0000000080020002 00000001ffffefff 0000000000000000 head: 00fff00000000003 ffffea0000b40a01 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 0x1d28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4756, tgid 4756 (dhcpcd), ts 87565741071, free_ts 83578732108 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1473 prep_new_page mm/page_alloc.c:1481 [inline] get_page_from_freelist+0x1353/0x2e50 mm/page_alloc.c:3425 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4683 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x56/0x110 mm/slub.c:2304 allocate_slab mm/slub.c:2467 [inline] new_slab+0x84/0x260 mm/slub.c:2520 ___slab_alloc+0xdac/0x1870 mm/slub.c:3706 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3796 __slab_alloc_node mm/slub.c:3849 [inline] slab_alloc_node mm/slub.c:4016 [inline] __do_kmalloc_node mm/slub.c:4148 [inline] __kmalloc_node_track_caller_noprof+0x355/0x430 mm/slub.c:4168 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:605 __alloc_skb+0x164/0x380 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1320 [inline] netlink_dump+0x2c1/0xcc0 net/netlink/af_netlink.c:2291 netlink_recvmsg+0xa0d/0xf30 net/netlink/af_netlink.c:1983 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x1f6/0x250 net/socket.c:1068 ____sys_recvmsg+0x21f/0x6b0 net/socket.c:2816 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2858 __sys_recvmsg+0x114/0x1e0 net/socket.c:2888 page last free pid 5111 tgid 5111 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1093 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2588 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+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3979 [inline] slab_alloc_node mm/slub.c:4028 [inline] kmem_cache_alloc_node_noprof+0x153/0x310 mm/slub.c:4071 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:664 alloc_skb include/linux/skbuff.h:1320 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6526 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2815 sock_alloc_send_skb include/net/sock.h:1778 [inline] mld_newpack.isra.0+0x1ed/0x790 net/ipv6/mcast.c:1746 add_grhead+0x299/0x340 net/ipv6/mcast.c:1849 add_grec+0x111e/0x1670 net/ipv6/mcast.c:1987 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2233 mld_send_initial_cr net/ipv6/mcast.c:2224 [inline] mld_dad_work+0x51/0x2f0 net/ipv6/mcast.c:2259 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 Memory state around the buggy address: ffff88802d028600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802d028680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802d028700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802d028780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802d028800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================