================================================================== 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+0xbfb/0xe30 fs/ext4/extents.c:946 Read of size 4 at addr ffff8881049dbe88 by task kworker/u4:4/314 CPU: 0 PID: 314 Comm: kworker/u4:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 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+0x10f/0x150 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+0xbfb/0xe30 fs/ext4/extents.c:946 ext4_ext_map_blocks+0x20c/0x6150 fs/ext4/extents.c:4197 ext4_map_blocks+0x979/0x1a50 fs/ext4/inode.c:676 mpage_map_one_extent fs/ext4/inode.c:2423 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2476 [inline] ext4_writepages+0x1260/0x30a0 fs/ext4/inode.c:2844 do_writepages+0x476/0x6d0 mm/page-writeback.c:2388 __writeback_single_inode+0xd9/0x9e0 fs/fs-writeback.c:1657 writeback_sb_inodes+0x9f3/0x1610 fs/fs-writeback.c:1940 wb_writeback+0x3eb/0x990 fs/fs-writeback.c:2116 wb_do_writeback fs/fs-writeback.c:2263 [inline] wb_workfn+0x3ac/0xf30 fs/fs-writeback.c:2304 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475 kthread+0x3f5/0x4f0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 418: 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+0xd4/0x100 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] __kmalloc+0x13d/0x2c0 mm/slub.c:4436 kmalloc include/linux/slab.h:624 [inline] kernfs_file_read_iter fs/kernfs/file.c:195 [inline] kernfs_fop_read_iter+0x15c/0x460 fs/kernfs/file.c:242 call_read_iter include/linux/fs.h:2212 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x6c0/0xc20 fs/read_write.c:485 ksys_read+0x14a/0x260 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 418: 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:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc4/0x270 mm/slub.c:4588 kernfs_file_read_iter fs/kernfs/file.c:234 [inline] kernfs_fop_read_iter+0x3bc/0x460 fs/kernfs/file.c:242 call_read_iter include/linux/fs.h:2212 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x6c0/0xc20 fs/read_write.c:485 ksys_read+0x14a/0x260 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 The buggy address belongs to the object at ffff8881049da000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3720 bytes to the right of 4096-byte region [ffff8881049da000, ffff8881049db000) The buggy address belongs to the page: page:ffffea0004127600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1049d8 head:ffffea0004127600 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 289, ts 21495860239, free_ts 21474933419 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2610 prep_new_page+0x1c/0x110 mm/page_alloc.c:2616 get_page_from_freelist+0x2d42/0x2dd0 mm/page_alloc.c:4492 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5829 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954 kmemdup+0x26/0x60 mm/util.c:132 __addrconf_sysctl_register+0xb6/0x3e0 net/ipv6/addrconf.c:7172 addrconf_sysctl_register+0x147/0x1a0 net/ipv6/addrconf.c:7237 ipv6_add_dev+0xc09/0x1150 net/ipv6/addrconf.c:456 addrconf_notify+0x582/0xe00 net/ipv6/addrconf.c:3618 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2070 [inline] call_netdevice_notifiers_extack net/core/dev.c:2082 [inline] call_netdevice_notifiers+0x119/0x190 net/core/dev.c:2096 register_netdevice+0x110a/0x1490 net/core/dev.c:10463 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1477 [inline] free_pcp_prepare mm/page_alloc.c:1549 [inline] free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3540 free_unref_page+0xae/0x540 mm/page_alloc.c:3622 free_the_page mm/page_alloc.c:808 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5905 __free_slab+0xe5/0x1e0 mm/slub.c:2025 free_slab mm/slub.c:2040 [inline] discard_slab mm/slub.c:2046 [inline] __unfreeze_partials+0x15a/0x190 mm/slub.c:2532 put_cpu_partial+0xc6/0x120 mm/slub.c:2612 __slab_free+0x1d4/0x290 mm/slub.c:3395 do_slab_free mm/slub.c:3514 [inline] ___cache_free+0x104/0x120 mm/slub.c:3535 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x11f/0x2c0 mm/slub.c:4954 kvasprintf+0xe3/0x1a0 lib/kasprintf.c:25 kvasprintf_const+0xf2/0x240 lib/kasprintf.c:49 Memory state around the buggy address: ffff8881049dbd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881049dbe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881049dbe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8881049dbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881049dbf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== EXT4-fs error (device loop0): ext4_map_blocks:742: inode #18: comm kworker/u4:4: lblock 0 mapped to illegal pblock 0 (length 1) EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (loop0): This should not happen!! Data will be lost EXT4-fs error (device loop0): __ext4_get_inode_loc:4365: comm kworker/u4:4: Invalid inode table block 15336116641672254676 in block_group 0 EXT4-fs error (device loop0): __ext4_get_inode_loc:4365: comm kworker/u4:4: Invalid inode table block 15336116641672254676 in block_group 0 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_vlan left promiscuous mode