================================================================== BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0x8e3/0x1230 lib/iov_iter.c:978 Read of size 2048 at addr ffff8880636e8800 by task kworker/u4:6/4106 CPU: 1 PID: 4106 Comm: kworker/u4:6 Not tainted 5.15.118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: loop0 loop_workfn Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 copy_page_from_iter_atomic+0x8e3/0x1230 lib/iov_iter.c:978 generic_perform_write+0x33a/0x5b0 mm/filemap.c:3784 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3903 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3935 do_iter_readv_writev+0x594/0x7a0 do_iter_write+0x1ea/0x760 fs/read_write.c:855 lo_write_bvec+0x297/0x740 drivers/block/loop.c:316 lo_write_simple drivers/block/loop.c:338 [inline] do_req_filebacked drivers/block/loop.c:656 [inline] loop_handle_cmd drivers/block/loop.c:2234 [inline] loop_process_work+0x2309/0x2af0 drivers/block/loop.c:2274 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 4854: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] __kmalloc+0x168/0x300 mm/slub.c:4407 kmalloc include/linux/slab.h:596 [inline] hfsplus_read_wrapper+0x4e3/0x13b0 fs/hfsplus/wrapper.c:180 hfsplus_fill_super+0x38a/0x1c90 fs/hfsplus/super.c:413 mount_bdev+0x2c9/0x3f0 fs/super.c:1378 legacy_get_tree+0xeb/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1508 do_new_mount+0x28b/0xae0 fs/namespace.c:2994 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8880636e8800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff8880636e8800, ffff8880636e8a00) The buggy address belongs to the page: page:ffffea00018dba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880636eb400 pfn:0x636e8 head:ffffea00018dba00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00007a8c08 ffffea0000787108 ffff888011c41c80 raw: ffff8880636eb400 000000000010000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3508, ts 341545866445, free_ts 339745215403 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] __kmalloc_node_track_caller+0x1f6/0x390 mm/slub.c:4958 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x12c/0x590 net/core/skbuff.c:427 __napi_alloc_skb+0x15c/0x2d0 net/core/skbuff.c:568 napi_alloc_skb include/linux/skbuff.h:3046 [inline] page_to_skb+0x294/0xd20 drivers/net/virtio_net.c:454 receive_mergeable drivers/net/virtio_net.c:1070 [inline] receive_buf+0x1218/0x6490 drivers/net/virtio_net.c:1180 virtnet_receive drivers/net/virtio_net.c:1472 [inline] virtnet_poll+0x629/0x1270 drivers/net/virtio_net.c:1585 __napi_poll+0xc7/0x440 net/core/dev.c:7012 napi_poll net/core/dev.c:7079 [inline] net_rx_action+0x617/0xda0 net/core/dev.c:7166 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] alloc_skb_with_frags+0xa3/0x780 net/core/skbuff.c:6121 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2497 unix_dgram_sendmsg+0x6fd/0x2090 net/unix/af_unix.c:1812 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_write_iter+0x39b/0x530 net/socket.c:1060 call_write_iter include/linux/fs.h:2103 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacf/0xe50 fs/read_write.c:594 Memory state around the buggy address: ffff8880636e8900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880636e8980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880636e8a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880636e8a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880636e8b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================