================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:82 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in gfs2_withdrawn fs/gfs2/util.h:187 [inline] BUG: KASAN: slab-use-after-free in gfs2_quotad+0x19c/0x930 fs/gfs2/quota.c:1587 Read of size 8 at addr ffff8880601f40a8 by task gfs2_quotad/syz/24253 CPU: 1 UID: 0 PID: 24253 Comm: gfs2_quotad/syz Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:82 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] gfs2_withdrawn fs/gfs2/util.h:187 [inline] gfs2_quotad+0x19c/0x930 fs/gfs2/quota.c:1587 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 24243: 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:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:6017 kmalloc_noprof include/linux/slab.h:968 [inline] kzalloc_noprof include/linux/slab.h:1210 [inline] init_sbd fs/gfs2/ops_fstype.c:79 [inline] gfs2_fill_super+0x11f/0x21b0 fs/gfs2/ops_fstype.c:1121 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1204 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x31a/0xcf0 fs/namespace.c:3839 do_mount fs/namespace.c:4162 [inline] __do_sys_mount fs/namespace.c:4351 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4328 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 24243: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2768 [inline] slab_free mm/slub.c:6911 [inline] kfree+0x1be/0x670 mm/slub.c:7209 free_sbd fs/gfs2/ops_fstype.c:72 [inline] gfs2_fill_super+0x14ef/0x21b0 fs/gfs2/ops_fstype.c:1316 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1204 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x31a/0xcf0 fs/namespace.c:3839 do_mount fs/namespace.c:4162 [inline] __do_sys_mount fs/namespace.c:4351 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4328 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880601f4000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 168 bytes inside of freed 8192-byte region [ffff8880601f4000, ffff8880601f6000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x601f0 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: f5(slab) raw: 00fff00000000040 ffff88813fea7280 ffffea0000a58c00 0000000000000005 raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fea7280 ffffea0000a58c00 0000000000000005 head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001807c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23674, tgid 23671 (syz.0.4183), ts 2052936643508, free_ts 1805799507626 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x23d/0x2a0 mm/page_alloc.c:1887 prep_new_page mm/page_alloc.c:1895 [inline] get_page_from_freelist+0x23a5/0x2440 mm/page_alloc.c:3948 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5236 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3303 [inline] allocate_slab+0x87/0x670 mm/slub.c:3478 new_slab mm/slub.c:3536 [inline] ___slab_alloc+0xdb6/0x17b0 mm/slub.c:4890 __slab_alloc+0x65/0x100 mm/slub.c:5013 __slab_alloc_node mm/slub.c:5089 [inline] slab_alloc_node mm/slub.c:5488 [inline] __do_kmalloc_node mm/slub.c:5893 [inline] __kmalloc_node_track_caller_noprof+0x5d4/0x820 mm/slub.c:6005 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:625 __alloc_skb+0x204/0x3b0 net/core/skbuff.c:707 alloc_skb include/linux/skbuff.h:1383 [inline] netlink_dump+0x167/0xe90 net/netlink/af_netlink.c:2284 netlink_recvmsg+0x676/0xa30 net/netlink/af_netlink.c:1976 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1093 ____sys_recvmsg+0x21e/0x4c0 net/socket.c:-1 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2872 do_recvmmsg+0x307/0x770 net/socket.c:2967 page last free pid 21459 tgid 21459 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1436 [inline] free_unref_folios+0xcc0/0x13e0 mm/page_alloc.c:3033 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] truncate_inode_pages_range+0x346/0xd90 mm/truncate.c:408 evict+0x607/0xae0 fs/inode.c:839 filename_unlinkat+0x42d/0x5f0 fs/namei.c:5542 coredump_file fs/coredump.c:903 [inline] do_coredump fs/coredump.c:1100 [inline] vfs_coredump+0x1c85/0x3e60 fs/coredump.c:1201 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x178/0x670 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 Memory state around the buggy address: ffff8880601f3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880601f4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880601f4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880601f4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880601f4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================