================================================================== 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 ffff888055d50738 by task v4l_id/5323 CPU: 0 PID: 5323 Comm: v4l_id Not tainted 6.1.129-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:427 kasan_report+0x136/0x160 mm/kasan/report.c:531 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:2153 v4l2_open+0x228/0x360 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x54a/0x630 fs/char_dev.c:414 do_dentry_open+0x7f9/0x10f0 fs/open.c:882 do_open fs/namei.c:3626 [inline] path_openat+0x2644/0x2e60 fs/namei.c:3783 do_filp_open+0x230/0x480 fs/namei.c:3810 do_sys_openat2+0x13b/0x4f0 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8242b169a4 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:00007ffefe9ea180 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffefe9ea398 RCX: 00007f8242b169a4 RDX: 0000000000000000 RSI: 00007ffefe9eaf1c RDI: 00000000ffffff9c RBP: 00007ffefe9eaf1c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffefe9ea3b0 R14: 0000558a6f69c670 R15: 00007f8242f94a80 Allocated by task 4256: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] em28xx_v4l2_init+0x103/0x2db0 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x11b/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 4256: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x1604/0x2db0 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x11b/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888055d50000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1848 bytes inside of 8192-byte region [ffff888055d50000, ffff888055d52000) The buggy address belongs to the physical page: page:ffffea0001575400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55d50 head:ffffea0001575400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e6bc00 dead000000000005 ffff888017c42280 raw: 0000000000000000 0000000080020002 00000001ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4338, tgid 4337 (syz.1.2), ts 80731646748, free_ts 22253024022 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa1/0x230 mm/slab_common.c:949 kmalloc_array include/linux/slab.h:615 [inline] kcalloc include/linux/slab.h:646 [inline] cache_create_net+0x7f/0x260 net/sunrpc/cache.c:1751 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:1948 [inline] gss_svc_init_net+0x54/0x430 net/sunrpc/auth_gss/svcauth_gss.c:1976 ops_init+0x35d/0x600 net/core/net_namespace.c:138 setup_net+0x4f9/0xc70 net/core/net_namespace.c:336 copy_net_ns+0x352/0x590 net/core/net_namespace.c:508 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x531/0xa40 kernel/fork.c:3201 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3479 free_contig_range+0x9a/0x150 mm/page_alloc.c:9565 destroy_args+0xfe/0x997 mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x46d/0x4c2 mm/debug_vm_pgtable.c:1354 do_one_initcall+0x265/0x8f0 init/main.c:1298 do_initcall_level+0x157/0x207 init/main.c:1371 do_initcalls+0x49/0x86 init/main.c:1387 kernel_init_freeable+0x45c/0x60f init/main.c:1626 kernel_init+0x19/0x290 init/main.c:1514 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff888055d50600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055d50680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888055d50700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888055d50780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055d50800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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