================================================================== BUG: KASAN: slab-use-after-free in crc16+0x1fb/0x280 lib/crc16.c:58 Read of size 1 at addr ffff88802a83c000 by task ext4lazyinit/24508 CPU: 0 PID: 24508 Comm: ext4lazyinit Not tainted 6.3.0-syzkaller-10197-g91ec4b0d11fe #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:319 [inline] print_report+0x163/0x540 mm/kasan/report.c:430 kasan_report+0x176/0x1b0 mm/kasan/report.c:536 crc16+0x1fb/0x280 lib/crc16.c:58 ext4_group_desc_csum+0x90f/0xc50 fs/ext4/super.c:3243 ext4_group_desc_csum_set+0x19b/0x240 fs/ext4/super.c:3266 ext4_init_inode_table+0x655/0x800 fs/ext4/ialloc.c:1612 ext4_run_li_request fs/ext4/super.c:3733 [inline] ext4_lazyinit_thread+0x789/0x19a0 fs/ext4/super.c:3824 kthread+0x2b2/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 5025: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:196 [inline] __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc_node_track_caller+0xb6/0x230 mm/slab_common.c:986 kmalloc_reserve+0xfe/0x240 net/core/skbuff.c:585 __alloc_skb+0x1b1/0x420 net/core/skbuff.c:654 alloc_skb include/linux/skbuff.h:1288 [inline] alloc_skb_with_frags+0xa8/0x750 net/core/skbuff.c:6370 sock_alloc_send_pskb+0x919/0xa50 net/core/sock.c:2729 unix_dgram_sendmsg+0x5b5/0x2050 net/unix/af_unix.c:1944 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] sock_write_iter+0x397/0x520 net/socket.c:1140 call_write_iter include/linux/fs.h:1854 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7da/0xbf0 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88802a83c000 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 0 bytes inside of freed 512-byte region [ffff88802a83c000, ffff88802a83c200) The buggy address belongs to the physical page: page:ffffea0000aa0f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802a83e400 pfn:0x2a83c head:ffffea0000aa0f00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88801d1e2d01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff88801244f140 ffffea0000ad2810 ffffea0000c32a10 raw: ffff88802a83e400 0000000000100003 00000001ffffffff ffff88801d1e2d01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4646, tgid 4646 (dhcpcd), ts 44763143205, free_ts 37172505681 prep_new_page mm/page_alloc.c:2553 [inline] get_page_from_freelist+0x3246/0x33c0 mm/page_alloc.c:4326 __alloc_pages+0x255/0x670 mm/page_alloc.c:5592 alloc_slab_page+0x6a/0x160 mm/slub.c:1851 allocate_slab mm/slub.c:1998 [inline] new_slab+0x84/0x2f0 mm/slub.c:2051 ___slab_alloc+0xa85/0x10a0 mm/slub.c:3193 __slab_alloc mm/slub.c:3292 [inline] __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x1b8/0x290 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:965 [inline] __kmalloc_node_track_caller+0xa5/0x230 mm/slab_common.c:986 kmalloc_reserve+0xfe/0x240 net/core/skbuff.c:585 __alloc_skb+0x1b1/0x420 net/core/skbuff.c:654 alloc_skb include/linux/skbuff.h:1288 [inline] alloc_skb_with_frags+0xa8/0x750 net/core/skbuff.c:6370 sock_alloc_send_pskb+0x919/0xa50 net/core/sock.c:2729 unix_dgram_sendmsg+0x5b5/0x2050 net/unix/af_unix.c:1944 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] sock_write_iter+0x397/0x520 net/socket.c:1140 call_write_iter include/linux/fs.h:1854 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7da/0xbf0 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1454 [inline] free_pcp_prepare mm/page_alloc.c:1504 [inline] free_unref_page_prepare+0xe2f/0xe70 mm/page_alloc.c:3388 free_unref_page+0x37/0x3f0 mm/page_alloc.c:3483 discard_slab mm/slub.c:2098 [inline] __unfreeze_partials+0x1b1/0x1f0 mm/slub.c:2637 put_cpu_partial+0x116/0x180 mm/slub.c:2713 qlist_free_all+0x22/0x60 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook+0x68/0x3a0 mm/slab.h:710 slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x11f/0x2e0 mm/slub.c:3476 getname_flags+0xbc/0x4e0 fs/namei.c:140 vfs_fstatat fs/stat.c:275 [inline] __do_sys_newfstatat fs/stat.c:446 [inline] __se_sys_newfstatat fs/stat.c:440 [inline] __x64_sys_newfstatat+0x12e/0x1d0 fs/stat.c:440 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88802a83bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802a83bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88802a83c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802a83c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802a83c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================