================================================================== 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 ffff88811990c730 by task v4l_id/8443 CPU: 1 UID: 0 PID: 8443 Comm: v4l_id Not tainted 6.13.0-rc3-syzkaller-g362a7993ed01 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 v4l2_fh_open+0x83/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63 em28xx_v4l2_open+0x250/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2153 v4l2_open+0x222/0x490 drivers/media/v4l2-core/v4l2-dev.c:429 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x6cb/0x1390 fs/open.c:945 vfs_open+0x82/0x3f0 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3987 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1428 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: 0033:0x7f3d9f7e19a4 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:00007ffebb726230 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffebb726448 RCX: 00007f3d9f7e19a4 RDX: 0000000000000000 RSI: 00007ffebb726f23 RDI: 00000000ffffff9c RBP: 00007ffebb726f23 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffebb726460 R14: 000055ceb22ac670 R15: 00007f3d9fc30a80 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:377 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2532 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+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 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:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x130/0x470 mm/slub.c:4761 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x22a4/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2901 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+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 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 ffff88811990c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1840 bytes inside of freed 8192-byte region [ffff88811990c000, ffff88811990e000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x119908 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042280 ffffea0004542600 dead000000000003 raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 0200000000000040 ffff888100042280 ffffea0004542600 dead000000000003 head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 0200000000000003 ffffea0004664201 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2954, tgid 2954 (syz-executor), ts 38171323228, free_ts 38137437363 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xe76/0x2b90 mm/page_alloc.c:3474 __alloc_pages_noprof+0x21c/0x22a0 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0xeb/0x400 mm/mempolicy.c:2269 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2589 [inline] new_slab+0x2c9/0x410 mm/slub.c:2642 ___slab_alloc+0xd1d/0x16e0 mm/slub.c:3830 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] __do_kmalloc_node mm/slub.c:4297 [inline] __kmalloc_noprof+0x154/0x4d0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] kmalloc_array_noprof include/linux/slab.h:946 [inline] cache_create_net+0xa0/0x220 net/sunrpc/cache.c:1745 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:2052 [inline] gss_svc_init_net+0x69/0x660 net/sunrpc/auth_gss/svcauth_gss.c:2080 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x21f/0x860 net/core/net_namespace.c:362 copy_net_ns+0x2b4/0x6c0 net/core/net_namespace.c:516 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x45d/0xa40 kernel/fork.c:3334 page last free pid 2992 tgid 2992 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0x661/0xe40 mm/page_alloc.c:2657 __put_partials+0x14c/0x170 mm/slub.c:3157 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x154/0x3b0 mm/slub.c:4175 vm_area_dup+0x1f/0x160 kernel/fork.c:487 __split_vma+0x181/0x1130 mm/vma.c:434 split_vma mm/vma.c:510 [inline] vma_modify+0x2ed/0x3b0 mm/vma.c:1528 vma_modify_flags+0x1c4/0x250 mm/vma.c:1546 mprotect_fixup+0x2c2/0xbe0 mm/mprotect.c:666 do_mprotect_pkey+0x981/0xcf0 mm/mprotect.c:840 __do_sys_mprotect mm/mprotect.c:861 [inline] __se_sys_mprotect mm/mprotect.c:858 [inline] __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:858 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: ffff88811990c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811990c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811990c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811990c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811990c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================