================================================================== BUG: KASAN: use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] BUG: KASAN: use-after-free in v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 Read of size 8 at addr ffff88807cb98900 by task v4l_id/3698 CPU: 0 PID: 3698 Comm: v4l_id Not tainted 5.15.167-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline] v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x15d/0xa10 drivers/media/usb/em28xx/em28xx-video.c:2163 v4l2_open+0x228/0x360 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x54a/0x630 fs/char_dev.c:414 do_dentry_open+0x807/0xfb0 fs/open.c:826 do_open fs/namei.c:3608 [inline] path_openat+0x2705/0x2f20 fs/namei.c:3742 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f87440359a4 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:00007ffe02656510 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffe02656728 RCX: 00007f87440359a4 RDX: 0000000000000000 RSI: 00007ffe02657f20 RDI: 00000000ffffff9c RBP: 00007ffe02657f20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe02656740 R14: 00005632f7ff6670 R15: 00007f874447ea80 Allocated by task 3684: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] __kmalloc_node_track_caller+0x195/0x390 mm/slub.c:4963 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x12c/0x590 net/core/skbuff.c:427 skb_copy+0x127/0x820 net/core/skbuff.c:1595 mac80211_hwsim_tx_frame_no_nl+0xe37/0x1840 drivers/net/wireless/mac80211_hwsim.c:1569 mac80211_hwsim_tx_frame+0x1cc/0x220 drivers/net/wireless/mac80211_hwsim.c:1788 mac80211_hwsim_beacon_tx+0x48f/0x8a0 drivers/net/wireless/mac80211_hwsim.c:1842 __iterate_interfaces+0x21e/0x4b0 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0xaf/0x140 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xa7/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_run_softirq+0x196/0x2c0 kernel/time/hrtimer.c:1769 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 sysvec_apic_timer_interrupt+0x43/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 Freed by task 154: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xf1/0x270 mm/slub.c:4559 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x73a/0x8a0 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] kfree_skb_reason+0xb3/0x170 net/core/skbuff.c:776 kfree_skb include/linux/skbuff.h:1123 [inline] ieee80211_iface_work+0x251/0xcc0 net/mac80211/iface.c:1497 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88807cb98800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 256 bytes inside of 512-byte region [ffff88807cb98800, ffff88807cb98a00) The buggy address belongs to the page: page:ffffea0001f2e600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7cb98 head:ffffea0001f2e600 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888017041c80 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3684, ts 54091444391, free_ts 54043358150 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] __kmalloc_node_track_caller+0x1f6/0x390 mm/slub.c:4958 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x12c/0x590 net/core/skbuff.c:427 skb_copy+0x127/0x820 net/core/skbuff.c:1595 mac80211_hwsim_tx_frame_no_nl+0xe37/0x1840 drivers/net/wireless/mac80211_hwsim.c:1569 mac80211_hwsim_tx_frame+0x1cc/0x220 drivers/net/wireless/mac80211_hwsim.c:1788 mac80211_hwsim_beacon_tx+0x48f/0x8a0 drivers/net/wireless/mac80211_hwsim.c:1842 __iterate_interfaces+0x21e/0x4b0 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0xaf/0x140 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xa7/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_run_softirq+0x196/0x2c0 kernel/time/hrtimer.c:1769 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 stack_depot_save+0x3ef/0x440 lib/stackdepot.c:335 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xd1/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] __kmalloc_track_caller+0x166/0x300 mm/slub.c:4930 kstrdup+0x31/0x70 mm/util.c:60 v9fs_session_init+0xfb/0x1910 fs/9p/v9fs.c:400 v9fs_mount+0x72/0x860 fs/9p/vfs_super.c:126 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1528 do_new_mount+0x2ba/0xb40 fs/namespace.c:3005 do_mount fs/namespace.c:3348 [inline] __do_sys_mount fs/namespace.c:3556 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88807cb98800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807cb98880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807cb98900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807cb98980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807cb98a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================