================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common+0xd18/0x2678 kernel/locking/mutex.c:678 Read of size 8 at addr ffff0000d9629908 by task jfsCommit/100 CPU: 0 UID: 0 PID: 100 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xa8/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0xb0/0x110 mm/kasan/report.c:595 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] __mutex_lock_common+0xd18/0x2678 kernel/locking/mutex.c:678 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 jfs_syncpt+0x2c/0x94 fs/jfs/jfs_logmgr.c:1039 txEnd+0x290/0x4f0 fs/jfs/jfs_txnmgr.c:550 txLazyCommit fs/jfs/jfs_txnmgr.c:2685 [inline] jfs_lazycommit+0x4b4/0x94c fs/jfs/jfs_txnmgr.c:2734 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Allocated by task 6961: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:77 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:573 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3a4/0x65c mm/slub.c:5748 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] open_inline_log fs/jfs/jfs_logmgr.c:1159 [inline] lmLogOpen+0x28c/0xd58 fs/jfs/jfs_logmgr.c:1069 jfs_mount_rw+0xe4/0x548 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x5d4/0xb6c fs/jfs/super.c:532 get_tree_bdev_flags+0x360/0x414 fs/super.c:1691 get_tree_bdev+0x2c/0x3c fs/super.c:1714 jfs_get_tree+0x28/0x38 fs/jfs/super.c:635 vfs_get_tree+0x90/0x28c fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x284/0x944 fs/namespace.c:3727 path_mount+0x5b4/0xdfc fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4215 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Freed by task 6554: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:77 __kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2523 [inline] slab_free mm/slub.c:6611 [inline] kfree+0x184/0x600 mm/slub.c:6818 lmLogClose+0x250/0x4c4 fs/jfs/jfs_logmgr.c:-1 jfs_umount+0x26c/0x350 fs/jfs/jfs_umount.c:114 jfs_put_super+0x90/0x188 fs/jfs/super.c:194 generic_shutdown_super+0x12c/0x2b8 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1722 deactivate_locked_super+0xc4/0x12c fs/super.c:473 deactivate_super+0xe0/0x100 fs/super.c:506 cleanup_mnt+0x31c/0x3ac fs/namespace.c:1327 __cleanup_mnt+0x20/0x30 fs/namespace.c:1334 task_work_run+0x1dc/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xfc/0x178 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline] el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 The buggy address belongs to the object at ffff0000d9629800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 264 bytes inside of freed 1024-byte region [ffff0000d9629800, ffff0000d9629c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x119628 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0001dc0 fffffdffc34d3000 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0001dc0 fffffdffc34d3000 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc3658a01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d9629800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d9629880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000d9629900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d9629980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d9629a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address dfff800000000006 KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [dfff800000000006] address between user and kernel address ranges Internal error: Oops: 0000000096000005 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 100 Comm: jfsCommit Tainted: G B syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 pstate: 23400005 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] pc : lmLogSync+0xf8/0x894 fs/jfs/jfs_logmgr.c:935 lr : write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] lr : lmLogSync+0xec/0x894 fs/jfs/jfs_logmgr.c:935 sp : ffff800099e77b00 x29: ffff800099e77bd0 x28: 1ffff00013680622 x27: dfff800000000000 x26: 1ffff00011f73124 x25: dfff800000000000 x24: ffff800099e77b20 x23: 0000000000000002 x22: ffff7000133cef64 x21: 0000000000000030 x20: ffff0000f7b8f6c8 x19: ffff0000d9629800 x18: 0000000079ffcdd9 x17: 3d3d3d3d3d3d3d3d x16: ffff80008ad5ae08 x15: ffff7000133cef6c x14: 1ffff000133cef68 x13: 0000000000000004 x12: ffffffffffffffff x11: ffff7000133cef6c x10: 0000000000ff0100 x9 : ffff8000973a41c0 x8 : 0000000000000006 x7 : 0000000000000000 x6 : ffff80008ae01948 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800081c3f718 x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000 Call trace: write_special_inodes fs/jfs/jfs_logmgr.c:207 [inline] (P) lmLogSync+0xf8/0x894 fs/jfs/jfs_logmgr.c:935 (P) jfs_syncpt+0x70/0x94 fs/jfs/jfs_logmgr.c:1041 txEnd+0x290/0x4f0 fs/jfs/jfs_txnmgr.c:550 txLazyCommit fs/jfs/jfs_txnmgr.c:2685 [inline] jfs_lazycommit+0x4b4/0x94c fs/jfs/jfs_txnmgr.c:2734 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Code: 97c109a1 f94002a8 9100c115 d343fea8 (387b6908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 97c109a1 bl 0xffffffffff042684 4: f94002a8 ldr x8, [x21] 8: 9100c115 add x21, x8, #0x30 c: d343fea8 lsr x8, x21, #3 * 10: 387b6908 ldrb w8, [x8, x27] <-- trapping instruction