================================================================== BUG: KASAN: use-after-free in pid_is_meaningful fs/gfs2/glock.c:1471 [inline] BUG: KASAN: use-after-free in dump_holder fs/gfs2/glock.c:2331 [inline] BUG: KASAN: use-after-free in gfs2_dump_glock+0x12a1/0x1830 fs/gfs2/glock.c:2445 Read of size 2 at addr ffff888054668020 by task syz.3.825/6652 CPU: 1 PID: 6652 Comm: syz.3.825 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 pid_is_meaningful fs/gfs2/glock.c:1471 [inline] dump_holder fs/gfs2/glock.c:2331 [inline] gfs2_dump_glock+0x12a1/0x1830 fs/gfs2/glock.c:2445 gfs2_consist_inode_i+0xf1/0x110 fs/gfs2/util.c:467 gfs2_dirent_scan+0x525/0x650 fs/gfs2/dir.c:602 gfs2_dir_read+0x7ff/0x1780 fs/gfs2/dir.c:1599 gfs2_readdir+0x14c/0x1b0 fs/gfs2/file.c:115 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xe5/0x250 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f702498f749 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:00007f7025796038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f7024be5fa0 RCX: 00007f702498f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f7024a13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7024be6038 R14: 00007f7024be5fa0 R15: 00007ffcbb481d68 Allocated by task 6651: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3404 alloc_task_struct_node kernel/fork.c:172 [inline] dup_task_struct+0x57/0x6b0 kernel/fork.c:981 copy_process+0x5bd/0x4020 kernel/fork.c:2181 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 __do_sys_clone3 kernel/fork.c:3056 [inline] __se_sys_clone3+0x2dc/0x360 kernel/fork.c:3040 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 21: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x290 mm/slub.c:3709 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x9c0/0x16a0 kernel/rcu/tree.c:2557 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 run_ksoftirqd+0x98/0xf0 kernel/softirq.c:963 smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x154/0x980 kernel/rcu/tree.c:2849 context_switch kernel/sched/core.c:5247 [inline] __schedule+0x10f4/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x97/0x280 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x2b9/0x590 kernel/sched/completion.c:138 rdmsr_safe_on_cpu+0x139/0x210 arch/x86/lib/msr-smp.c:183 msr_read+0x10a/0x1b0 arch/x86/kernel/msr.c:67 vfs_read+0x2c0/0x920 fs/read_write.c:468 ksys_read+0x143/0x240 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x154/0x980 kernel/rcu/tree.c:2849 put_task_struct_rcu_user kernel/exit.c:231 [inline] release_task+0x14ad/0x1600 kernel/exit.c:281 wait_task_zombie kernel/exit.c:1208 [inline] wait_consider_task+0x1978/0x2e40 kernel/exit.c:1435 do_wait_thread kernel/exit.c:1498 [inline] do_wait+0x31c/0xb60 kernel/exit.c:1615 kernel_wait4+0x1ab/0x270 kernel/exit.c:1778 __do_sys_wait4 kernel/exit.c:1806 [inline] __se_sys_wait4 kernel/exit.c:1802 [inline] __x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1802 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888054668000 which belongs to the cache task_struct of size 7360 The buggy address is located 32 bytes inside of 7360-byte region [ffff888054668000, ffff888054669cc0) The buggy address belongs to the physical page: page:ffffea0001519a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54668 head:ffffea0001519a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801ffda901 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888140008500 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88801ffda901 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 4266, tgid 4266 (syz-executor), ts 116449745133, free_ts 114844165402 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1230 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] kmem_cache_alloc_node+0x1e5/0x320 mm/slub.c:3404 alloc_task_struct_node kernel/fork.c:172 [inline] dup_task_struct+0x57/0x6b0 kernel/fork.c:981 copy_process+0x5bd/0x4020 kernel/fork.c:2181 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 __do_sys_clone kernel/fork.c:2898 [inline] __se_sys_clone kernel/fork.c:2882 [inline] __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3383 getname_flags+0xb7/0x500 fs/namei.c:139 user_path_at_empty+0x28/0x60 fs/namei.c:2912 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1829 [inline] __do_sys_umount fs/namespace.c:1837 [inline] __se_sys_umount fs/namespace.c:1835 [inline] __x64_sys_umount+0xf1/0x160 fs/namespace.c:1835 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888054667f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054667f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888054668000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888054668080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054668100: fb fb fb 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