================================================================== BUG: KASAN: slab-out-of-bounds in ext4_ext_split fs/ext4/extents.c:1115 [inline] BUG: KASAN: slab-out-of-bounds in ext4_ext_create_new_leaf fs/ext4/extents.c:1414 [inline] BUG: KASAN: slab-out-of-bounds in ext4_ext_insert_extent+0x1cf8/0x45d0 fs/ext4/extents.c:2098 Read of size 8 at addr ffff88810acf5e80 by task syz.2.2555/9198 CPU: 1 PID: 9198 Comm: syz.2.2555 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 ext4_ext_split fs/ext4/extents.c:1115 [inline] ext4_ext_create_new_leaf fs/ext4/extents.c:1414 [inline] ext4_ext_insert_extent+0x1cf8/0x45d0 fs/ext4/extents.c:2098 ext4_ext_map_blocks+0x17a9/0x5dd0 fs/ext4/extents.c:4356 ext4_map_blocks+0x985/0x1bd0 fs/ext4/inode.c:674 _ext4_get_block+0x1d1/0x4e0 fs/ext4/inode.c:817 ext4_get_block_unwritten+0x2a/0x40 fs/ext4/inode.c:848 ext4_block_write_begin+0x573/0x1340 fs/ext4/inode.c:1101 ext4_write_begin+0x67e/0x1690 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x478/0xf10 fs/ext4/inode.c:3033 generic_perform_write+0x2ce/0x540 mm/filemap.c:3509 ext4_buffered_write_iter+0x4b8/0x640 fs/ext4/file.c:271 ext4_file_write_iter+0x53f/0x1980 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x758/0xdc0 fs/read_write.c:605 ksys_pwrite64 fs/read_write.c:712 [inline] __do_sys_pwrite64 fs/read_write.c:722 [inline] __se_sys_pwrite64 fs/read_write.c:719 [inline] __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:719 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fba74182799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fba72bdd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007fba743fbfa0 RCX: 00007fba74182799 RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000009 RBP: 00007fba74218bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fba743fc038 R14: 00007fba743fbfa0 R15: 00007ffe3923e488 Allocated by task 8642: 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:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1a4/0x330 mm/slub.c:4038 __kmalloc_node include/linux/slab.h:421 [inline] kmalloc_node include/linux/slab.h:578 [inline] __vmalloc_area_node mm/vmalloc.c:2520 [inline] __vmalloc_node_range+0x29f/0x790 mm/vmalloc.c:2629 __vmalloc_node mm/vmalloc.c:2689 [inline] __vmalloc+0x79/0x90 mm/vmalloc.c:2703 __vmalloc_array mm/util.c:706 [inline] __vcalloc+0x36/0x50 mm/util.c:729 kvm_alloc_memslot_metadata arch/x86/kvm/x86.c:10867 [inline] kvm_arch_prepare_memory_region+0x194/0x780 arch/x86/kvm/x86.c:10930 kvm_set_memslot+0x206/0x1440 virt/kvm/kvm_main.c:1289 __kvm_set_memory_region+0xa74/0xc50 virt/kvm/kvm_main.c:1448 kvm_set_memory_region virt/kvm/kvm_main.c:1469 [inline] kvm_vm_ioctl_set_memory_region+0x6f/0xa0 virt/kvm/kvm_main.c:1481 kvm_vm_ioctl+0x822/0xad0 virt/kvm/kvm_main.c:3829 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88810acf5e60 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 24 bytes to the right of 8-byte region [ffff88810acf5e60, ffff88810acf5e68) The buggy address belongs to the page: page:ffffea00042b3d40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10acf5 flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea0004196240 0000000300000003 ffff888100043c80 raw: 0000000000000000 0000000080660066 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 4413690604, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc+0x1fe/0x330 mm/slub.c:4034 __kmalloc_node include/linux/slab.h:421 [inline] kmalloc_array_node include/linux/slab.h:630 [inline] kcalloc_node include/linux/slab.h:635 [inline] blk_mq_realloc_hw_ctxs+0xc5/0x16c0 block/blk-mq.c:3271 blk_mq_init_allocated_queue+0x409/0x17c0 block/blk-mq.c:3361 blk_mq_init_queue_data block/blk-mq.c:3180 [inline] blk_mq_init_queue+0x6e/0xd0 block/blk-mq.c:3190 scsi_mq_alloc_queue+0x42/0x140 drivers/scsi/scsi_lib.c:1900 scsi_alloc_sdev+0x60d/0x920 drivers/scsi/scsi_scan.c:284 scsi_probe_and_add_lun+0x17d/0x33a0 drivers/scsi/scsi_scan.c:1098 __scsi_scan_target+0x1d2/0xbf0 drivers/scsi/scsi_scan.c:1581 scsi_scan_channel drivers/scsi/scsi_scan.c:1669 [inline] scsi_scan_host_selected+0x343/0x5f0 drivers/scsi/scsi_scan.c:1698 do_scsi_scan_host drivers/scsi/scsi_scan.c:1837 [inline] scsi_scan_host+0x39e/0x660 drivers/scsi/scsi_scan.c:1867 page_owner free stack trace missing Memory state around the buggy address: ffff88810acf5d80: fc fc fc fb fc fc fc fc 00 fc fc fc fc fb fc fc ffff88810acf5e00: fc fc fa fc fc fc fc 00 fc fc fc fc fb fc fc fc >ffff88810acf5e80: fc 00 fc fc fc fc 00 fc fc fc fc fb fc fc fc fc ^ ffff88810acf5f00: fb fc fc fc fc fa fc fc fc fc fb fc fc fc fc fb ffff88810acf5f80: fc fc fc fc fb fc fc fc fc 00 fc fc fc fc fc fc ==================================================================