================================================================== BUG: KASAN: slab-use-after-free in write_special_inodes+0x155/0x180 fs/jfs/jfs_logmgr.c:208 Read of size 8 at addr ffff888061be1428 by task syz-executor/7496 CPU: 1 UID: 0 PID: 7496 Comm: syz-executor 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 lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595 write_special_inodes+0x155/0x180 fs/jfs/jfs_logmgr.c:208 jfs_flush_journal+0x469/0x8c0 fs/jfs/jfs_logmgr.c:1572 jfs_umount+0x17a/0x410 fs/jfs/jfs_umount.c:58 jfs_put_super+0x88/0x1a0 fs/jfs/super.c:194 generic_shutdown_super+0x15f/0x360 fs/super.c:643 kill_block_super+0x3b/0xa0 fs/super.c:1722 deactivate_locked_super+0xc1/0x1b0 fs/super.c:474 deactivate_super fs/super.c:507 [inline] deactivate_super+0xe7/0x110 fs/super.c:503 cleanup_mnt+0x21f/0x450 fs/namespace.c:1318 task_work_run+0x150/0x240 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:44 [inline] exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5db9d9bf17 Code: a2 c7 05 7c 96 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd17d59e88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f5db9e0471f RCX: 00007f5db9d9bf17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd17d59f40 RBP: 00007ffd17d59f40 R08: 00007ffd17d5af40 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd17d5afd0 R13: 00007f5db9e0471f R14: 0000000000055f0b R15: 00007ffd17d5b010 Allocated by task 8126: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] jfs_fill_super+0xca/0xf50 fs/jfs/super.c:452 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1691 vfs_get_tree+0x92/0x320 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7d0/0x23c0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5821: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1c7/0x690 mm/slub.c:6882 generic_shutdown_super+0x15f/0x360 fs/super.c:643 kill_block_super+0x3b/0xa0 fs/super.c:1722 deactivate_locked_super+0xc1/0x1b0 fs/super.c:474 deactivate_super fs/super.c:507 [inline] deactivate_super+0xe7/0x110 fs/super.c:503 cleanup_mnt+0x21f/0x450 fs/namespace.c:1318 task_work_run+0x150/0x240 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:44 [inline] exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888061be1400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 40 bytes inside of freed 256-byte region [ffff888061be1400, ffff888061be1500) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x61be0 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ff26b40 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ff26b40 dead000000000122 0000000000000000 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea000186f801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 8031, tgid 8028 (syz.1.440), ts 342542648094, free_ts 340508117894 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c4/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x618/0x9c0 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] io_cache_alloc_new+0x45/0xe0 io_uring/alloc_cache.c:40 io_cache_alloc io_uring/alloc_cache.h:59 [inline] io_uring_alloc_async_data io_uring/io_uring.h:342 [inline] io_rw_alloc_async io_uring/rw.c:209 [inline] __io_prep_rw+0x21d/0xfa0 io_uring/rw.c:268 io_prep_rw+0x76/0x2c0 io_uring/rw.c:328 io_prep_rwv io_uring/rw.c:350 [inline] io_prep_writev+0x23/0xa0 io_uring/rw.c:370 io_init_req io_uring/io_uring.c:2235 [inline] io_submit_sqe io_uring/io_uring.c:2282 [inline] io_submit_sqes+0xa4b/0x21c0 io_uring/io_uring.c:2435 __do_sys_io_uring_enter+0x6b4/0x15b0 io_uring/io_uring.c:3285 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 8011 tgid 8001 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973 kasan_depopulate_vmalloc_pte+0x5d/0x80 mm/kasan/shadow.c:484 apply_to_pte_range mm/memory.c:3185 [inline] apply_to_pmd_range mm/memory.c:3229 [inline] apply_to_pud_range mm/memory.c:3265 [inline] apply_to_p4d_range mm/memory.c:3301 [inline] __apply_to_page_range+0xb1d/0x1520 mm/memory.c:3337 __kasan_release_vmalloc+0xd7/0xe0 mm/kasan/shadow.c:602 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2282 [inline] purge_vmap_node+0x1c6/0xaa0 mm/vmalloc.c:2299 __purge_vmap_area_lazy+0x8e5/0xbc0 mm/vmalloc.c:2389 _vm_unmap_aliases+0x40e/0x630 mm/vmalloc.c:2983 change_page_attr_set_clr+0x252/0x4a0 arch/x86/mm/pat/set_memory.c:2082 cpa_set_pages_array arch/x86/mm/pat/set_memory.c:2137 [inline] _set_pages_array+0x1ab/0x2c0 arch/x86/mm/pat/set_memory.c:2521 drm_gem_shmem_get_pages_locked+0x380/0x4b0 drivers/gpu/drm/drm_gem_shmem_helper.c:254 drm_gem_shmem_pin_locked+0x224/0x470 drivers/gpu/drm/drm_gem_shmem_helper.c:301 drm_gem_map_attach+0x184/0x270 drivers/gpu/drm/drm_prime.c:621 dma_buf_dynamic_attach drivers/dma-buf/dma-buf.c:966 [inline] dma_buf_dynamic_attach+0x1f3/0x530 drivers/dma-buf/dma-buf.c:941 drm_gem_shmem_prime_import_no_map drivers/gpu/drm/drm_gem_shmem_helper.c:868 [inline] drm_gem_shmem_prime_import_no_map+0x67/0x390 drivers/gpu/drm/drm_gem_shmem_helper.c:849 drm_gem_prime_fd_to_handle+0x1a3/0x5e0 drivers/gpu/drm/drm_prime.c:314 drm_prime_fd_to_handle_ioctl+0xd6/0x110 drivers/gpu/drm/drm_prime.c:372 Memory state around the buggy address: ffff888061be1300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888061be1380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888061be1400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888061be1480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888061be1500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 1 UID: 0 PID: 7496 Comm: syz-executor Tainted: G B L syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:write_special_inodes+0xa9/0x180 fs/jfs/jfs_logmgr.c:208 Code: 2e e8 1b 60 dd 07 48 8d 7b 28 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 b6 00 00 00 4c 8b 6b 28 49 8d 7d 30 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 93 00 00 00 49 8b 7d 30 2e e8 e3 5f dd 07 48 8d RSP: 0018:ffffc9002113fbb0 EFLAGS: 00010216 RAX: 0000000000000006 RBX: ffff888061be1400 RCX: ffffffff81c58c7f RDX: ffff88802cafbd00 RSI: ffffffff81c58c8d RDI: 0000000000000030 RBP: dffffc0000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 6e696c6261736944 R12: ffffffff823e08c0 R13: 0000000000000000 R14: ffff888023b57800 R15: ffff888023b579d0 FS: 000055558244e500(0000) GS:ffff8881246de000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f23c83e1198 CR3: 000000007e240000 CR4: 0000000000350ef0 Call Trace: jfs_flush_journal+0x469/0x8c0 fs/jfs/jfs_logmgr.c:1572 jfs_umount+0x17a/0x410 fs/jfs/jfs_umount.c:58 jfs_put_super+0x88/0x1a0 fs/jfs/super.c:194 generic_shutdown_super+0x15f/0x360 fs/super.c:643 kill_block_super+0x3b/0xa0 fs/super.c:1722 deactivate_locked_super+0xc1/0x1b0 fs/super.c:474 deactivate_super fs/super.c:507 [inline] deactivate_super+0xe7/0x110 fs/super.c:503 cleanup_mnt+0x21f/0x450 fs/namespace.c:1318 task_work_run+0x150/0x240 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:44 [inline] exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5db9d9bf17 Code: a2 c7 05 7c 96 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd17d59e88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f5db9e0471f RCX: 00007f5db9d9bf17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd17d59f40 RBP: 00007ffd17d59f40 R08: 00007ffd17d5af40 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd17d5afd0 R13: 00007f5db9e0471f R14: 0000000000055f0b R15: 00007ffd17d5b010 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:write_special_inodes+0xa9/0x180 fs/jfs/jfs_logmgr.c:208 Code: 2e e8 1b 60 dd 07 48 8d 7b 28 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 b6 00 00 00 4c 8b 6b 28 49 8d 7d 30 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 93 00 00 00 49 8b 7d 30 2e e8 e3 5f dd 07 48 8d RSP: 0018:ffffc9002113fbb0 EFLAGS: 00010216 RAX: 0000000000000006 RBX: ffff888061be1400 RCX: ffffffff81c58c7f RDX: ffff88802cafbd00 RSI: ffffffff81c58c8d RDI: 0000000000000030 RBP: dffffc0000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 6e696c6261736944 R12: ffffffff823e08c0 R13: 0000000000000000 R14: ffff888023b57800 R15: ffff888023b579d0 FS: 000055558244e500(0000) GS:ffff8881246de000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f84d1fe0ad8 CR3: 000000007e240000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 2e e8 1b 60 dd 07 cs call 0x7dd6021 6: 48 8d 7b 28 lea 0x28(%rbx),%rdi a: 48 89 f8 mov %rdi,%rax d: 48 c1 e8 03 shr $0x3,%rax 11: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) 15: 0f 85 b6 00 00 00 jne 0xd1 1b: 4c 8b 6b 28 mov 0x28(%rbx),%r13 1f: 49 8d 7d 30 lea 0x30(%r13),%rdi 23: 48 89 f8 mov %rdi,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction 2e: 0f 85 93 00 00 00 jne 0xc7 34: 49 8b 7d 30 mov 0x30(%r13),%rdi 38: 2e e8 e3 5f dd 07 cs call 0x7dd6021 3e: 48 rex.W 3f: 8d .byte 0x8d