================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic_dec include/linux/atomic/atomic-instrumented.h:244 [inline] BUG: KASAN: use-after-free in gfs2_qd_dispose fs/gfs2/quota.c:137 [inline] BUG: KASAN: use-after-free in gfs2_qd_shrink_scan+0x61a/0x820 fs/gfs2/quota.c:175 Write of size 4 at addr ffff888072948a70 by task syz.1.125/5912 CPU: 1 PID: 5912 Comm: syz.1.125 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_dec include/linux/atomic/atomic-instrumented.h:244 [inline] gfs2_qd_dispose fs/gfs2/quota.c:137 [inline] gfs2_qd_shrink_scan+0x61a/0x820 fs/gfs2/quota.c:175 do_shrink_slab+0x510/0xd00 mm/vmscan.c:765 shrink_slab+0x1b1/0x770 mm/vmscan.c:925 drop_slab_node+0xf3/0x180 mm/vmscan.c:960 drop_slab+0x81/0x110 mm/vmscan.c:970 drop_caches_sysctl_handler+0xbe/0x160 fs/drop_caches.c:66 proc_sys_call_handler+0x458/0x6c0 fs/proc/proc_sysctl.c:588 do_iter_readv_writev+0x497/0x600 fs/read_write.c:-1 do_iter_write+0x205/0x7b0 fs/read_write.c:855 vfs_writev fs/read_write.c:928 [inline] do_writev+0x254/0x410 fs/read_write.c:971 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f45b14db759 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f45b075b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f45b1692f80 RCX: 00007f45b14db759 RDX: 0000000000000001 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f45b154e75e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f45b1692f80 R15: 00007ffe57746e38 Allocated by task 5909: 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 mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] init_sbd fs/gfs2/ops_fstype.c:77 [inline] gfs2_fill_super+0x13f/0x1f50 fs/gfs2/ops_fstype.c:1151 get_tree_bdev+0x3f1/0x610 fs/super.c:1325 gfs2_get_tree+0x4d/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3025 do_mount fs/namespace.c:3368 [inline] __do_sys_mount fs/namespace.c:3576 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 4946: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888072948000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2672 bytes inside of 8192-byte region [ffff888072948000, ffff88807294a000) The buggy address belongs to the page: page:ffffea0001ca5200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807294c000 pfn:0x72948 head:ffffea0001ca5200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001c31400 0000000300000003 ffff888016842280 raw: ffff88807294c000 0000000080020001 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 4894, ts 85511579144, free_ts 85498828625 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node+0x200/0x3b0 mm/slub.c:4456 kmalloc_node include/linux/slab.h:627 [inline] kvmalloc_node+0x84/0x130 mm/util.c:619 kvmalloc include/linux/mm.h:816 [inline] kvmalloc_array include/linux/mm.h:834 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0x35f/0x6a0 net/sched/sch_generic.c:806 qdisc_create_dflt+0x11a/0x430 net/sched/sch_generic.c:957 attach_one_default_qdisc net/sched/sch_generic.c:1113 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2379 [inline] attach_default_qdiscs net/sched/sch_generic.c:1131 [inline] dev_activate+0x331/0x12b0 net/sched/sch_generic.c:1190 __dev_open+0x32c/0x420 net/core/dev.c:1546 __dev_change_flags+0x20a/0x6a0 net/core/dev.c:8853 dev_change_flags+0x82/0x1a0 net/core/dev.c:8924 do_setlink+0xc01/0x3980 net/core/rtnetlink.c:2779 __rtnl_newlink net/core/rtnetlink.c:3450 [inline] rtnl_newlink+0x1419/0x17d0 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507 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+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0x645/0xbc0 net/netlink/af_netlink.c:1893 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2071 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888072948900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888072948980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888072948a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888072948a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888072948b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================