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Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/6c95be5ca2c8/disk-734bef54.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/975644b166ab/vmlinux-734bef54.xz kernel image: https://storage.googleapis.com/syzbot-assets/131e7835977a/bzImage-734bef54.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+49c659b5564b2a44083c@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:419 [inline] BUG: KASAN: slab-use-after-free in jffs2_erase_pending_blocks+0x217/0x2400 fs/jffs2/erase.c:108 Read of size 8 at addr ffff88803c752228 by task jffs2_gcd_mtd0/8922 CPU: 1 UID: 0 PID: 8922 Comm: jffs2_gcd_mtd0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 list_empty include/linux/list.h:419 [inline] jffs2_erase_pending_blocks+0x217/0x2400 fs/jffs2/erase.c:108 jffs2_garbage_collect_pass+0x6cc/0x2170 fs/jffs2/gc.c:253 jffs2_garbage_collect_thread+0x693/0x720 fs/jffs2/background.c:155 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8839: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3d0/0x670 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] jffs2_init_fs_context+0x4f/0xc0 fs/jffs2/super.c:314 alloc_fs_context+0x99e/0xd00 fs/fs_context.c:295 do_new_mount+0x177/0xb00 fs/namespace.c:3966 do_mount fs/namespace.c:4350 [inline] __do_sys_mount fs/namespace.c:4565 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4542 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7208: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x1c5/0x6d0 mm/slub.c:6802 deactivate_locked_super+0xbe/0x110 fs/super.c:586 cleanup_mnt+0x204/0x2a0 fs/namespace.c:1396 task_work_run+0x1d9/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803c752000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 552 bytes inside of freed 4096-byte region [ffff88803c752000, ffff88803c753000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3c750 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813ff11140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813ff11140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 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 5254, tgid 5254 (dhcpcd), ts 52755560116 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2591/0x2600 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x230/0x5c0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab+0x7d/0x620 mm/slub.c:3462 new_slab mm/slub.c:3513 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7418 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x339/0x690 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_node_track_caller_noprof+0x619/0x7b0 mm/slub.c:5545 kmalloc_reserve net/core/skbuff.c:638 [inline] __alloc_skb+0x2c1/0x7a0 net/core/skbuff.c:716 alloc_skb include/linux/skbuff.h:1390 [inline] nlmsg_new include/net/netlink.h:1055 [inline] ctrl_build_family_msg net/netlink/genetlink.c:1387 [inline] ctrl_getfamily+0x3d0/0x5c0 net/netlink/genetlink.c:1467 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2576 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x90c/0xac0 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 page last free pid 5254 tgid 5254 ts 52751440575 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xf8e/0x1070 mm/page_alloc.c:2962 skb_release_all net/core/skbuff.c:1188 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1202 netlink_recvmsg+0x5ce/0xa70 net/netlink/af_netlink.c:1998 sock_recvmsg_nosec net/socket.c:1154 [inline] sock_recvmsg+0x196/0x1e0 net/socket.c:1176 ____sys_recvmsg+0x1f6/0x510 net/socket.c:2935 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2977 __sys_recvmsg net/socket.c:3010 [inline] __do_sys_recvmsg net/socket.c:3016 [inline] __se_sys_recvmsg net/socket.c:3013 [inline] __x64_sys_recvmsg+0x1b4/0x290 net/socket.c:3013 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803c752100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803c752180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803c752200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803c752280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803c752300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup