================================================================== BUG: KASAN: slab-out-of-bounds in ext4_ext_binsearch fs/ext4/extents.c:827 [inline] BUG: KASAN: slab-out-of-bounds in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946 Read of size 4 at addr ffff888111e99018 by task kworker/u4:1/10 CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 5.15.189-syzkaller-00091-gf32b52534f1d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_binsearch fs/ext4/extents.c:827 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946 ext4_ext_map_blocks+0x1de/0x6280 fs/ext4/extents.c:4166 ext4_map_blocks+0x97b/0x1b20 fs/ext4/inode.c:674 mpage_map_one_extent fs/ext4/inode.c:2421 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] ext4_writepages+0x11e7/0x2f90 fs/ext4/inode.c:2842 do_writepages+0x48a/0x6c0 mm/page-writeback.c:2388 __writeback_single_inode+0xd5/0x9c0 fs/fs-writeback.c:1647 writeback_sb_inodes+0x9c0/0x1590 fs/fs-writeback.c:1930 wb_writeback+0x3f1/0x980 fs/fs-writeback.c:2106 wb_do_writeback fs/fs-writeback.c:2253 [inline] wb_workfn+0x38f/0xe20 fs/fs-writeback.c:2294 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 381: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] __kmalloc+0x13d/0x2c0 mm/slub.c:4431 __kmalloc_node include/linux/slab.h:484 [inline] kmalloc_node include/linux/slab.h:639 [inline] kvmalloc_node+0x206/0x300 mm/util.c:621 kvmalloc include/linux/mm.h:851 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x1fc/0xd30 fs/seq_file.c:210 kernfs_fop_read_iter+0x147/0x470 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2206 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x68b/0xbe0 fs/read_write.c:485 ksys_read+0x140/0x240 fs/read_write.c:623 __do_sys_read fs/read_write.c:633 [inline] __se_sys_read fs/read_write.c:631 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:631 x64_sys_call+0x96d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1 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 381: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749 slab_free mm/slub.c:3521 [inline] kfree+0xc4/0x270 mm/slub.c:4583 kvfree+0x35/0x40 mm/util.c:661 seq_release+0x57/0x70 fs/seq_file.c:355 kernfs_fop_release+0x1af/0x250 fs/kernfs/file.c:761 __fput+0x20b/0x8b0 fs/file_table.c:311 ____fput+0x15/0x20 fs/file_table.c:339 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 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 ffff888111e98000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 24 bytes to the right of 4096-byte region [ffff888111e98000, ffff888111e99000) The buggy address belongs to the page: page:ffffea000447a600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111e98 head:ffffea000447a600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043380 raw: 0000000000000000 0000000000040004 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 101, ts 6302472690, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5795 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1932 [inline] new_slab+0xa1/0x4d0 mm/slub.c:1995 ___slab_alloc+0x381/0x810 mm/slub.c:3028 __slab_alloc+0x49/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc_trace+0x146/0x270 mm/slub.c:3267 kmalloc include/linux/slab.h:616 [inline] kzalloc include/linux/slab.h:747 [inline] uevent_show+0x160/0x330 drivers/base/core.c:2413 dev_attr_show+0x56/0xd0 drivers/base/core.c:2120 sysfs_kf_seq_show+0x266/0x3d0 fs/sysfs/file.c:61 kernfs_seq_show+0x119/0x160 fs/kernfs/file.c:168 seq_read_iter+0x490/0xd30 fs/seq_file.c:230 kernfs_fop_read_iter+0x147/0x470 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2206 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x68b/0xbe0 fs/read_write.c:485 ksys_read+0x140/0x240 fs/read_write.c:623 page_owner free stack trace missing Memory state around the buggy address: ffff888111e98f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111e98f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888111e99000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888111e99080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888111e99100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ------------[ cut here ]------------ kernel BUG at fs/ext4/inode.c:2433! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 10 Comm: kworker/u4:1 Tainted: G B 5.15.189-syzkaller-00091-gf32b52534f1d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: writeback wb_workfn (flush-7:5) RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2433 [inline] RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] RIP: 0010:ext4_writepages+0x2eed/0x2f90 fs/ext4/inode.c:2842 Code: 00 74 08 48 89 df e8 22 01 ce ff 48 8b 3b 48 8b 74 24 28 48 8b 54 24 30 44 89 e9 45 89 f0 e8 6a 9b 07 00 eb 51 e8 23 86 8f ff <0f> 0b e8 1c 86 8f ff eb 2f e8 15 86 8f ff eb 5f e8 0e 86 8f ff 31 RSP: 0018:ffffc900000a7100 EFLAGS: 00010293 RAX: ffffffff81d929ad RBX: ffff88812e87aa40 RCX: ffff888100274f00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900000a7470 R08: dffffc0000000000 R09: ffffed1025d0f541 R10: ffffed1025d0f541 R11: 1ffff11025d0f540 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e00dff8 CR3: 000000010d32e000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_writepages+0x48a/0x6c0 mm/page-writeback.c:2388 __writeback_single_inode+0xd5/0x9c0 fs/fs-writeback.c:1647 writeback_sb_inodes+0x9c0/0x1590 fs/fs-writeback.c:1930 wb_writeback+0x3f1/0x980 fs/fs-writeback.c:2106 wb_do_writeback fs/fs-writeback.c:2253 [inline] wb_workfn+0x38f/0xe20 fs/fs-writeback.c:2294 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Modules linked in: ---[ end trace d51f710e507c56bf ]--- RIP: 0010:mpage_map_one_extent fs/ext4/inode.c:2433 [inline] RIP: 0010:mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] RIP: 0010:ext4_writepages+0x2eed/0x2f90 fs/ext4/inode.c:2842 Code: 00 74 08 48 89 df e8 22 01 ce ff 48 8b 3b 48 8b 74 24 28 48 8b 54 24 30 44 89 e9 45 89 f0 e8 6a 9b 07 00 eb 51 e8 23 86 8f ff <0f> 0b e8 1c 86 8f ff eb 2f e8 15 86 8f ff eb 5f e8 0e 86 8f ff 31 RSP: 0018:ffffc900000a7100 EFLAGS: 00010293 RAX: ffffffff81d929ad RBX: ffff88812e87aa40 RCX: ffff888100274f00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900000a7470 R08: dffffc0000000000 R09: ffffed1025d0f541 R10: ffffed1025d0f541 R11: 1ffff11025d0f540 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e00dff8 CR3: 000000010d32e000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000008000000f DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400