================================================================== BUG: KASAN: use-after-free in get_disk_and_module block/genhd.c:1787 [inline] BUG: KASAN: use-after-free in exact_lock+0x38/0xd0 block/genhd.c:677 Read of size 8 at addr ffff8881009a4460 by task syz.0.6166/24928 CPU: 0 PID: 24928 Comm: syz.0.6166 Tainted: G W 5.10.234-syzkaller-00023-g3f5f2283d684 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 get_disk_and_module block/genhd.c:1787 [inline] exact_lock+0x38/0xd0 block/genhd.c:677 kobj_lookup+0x294/0x430 drivers/base/map.c:119 get_gendisk+0xf7/0x3d0 block/genhd.c:1001 bdev_get_gendisk fs/block_dev.c:1110 [inline] __blkdev_get+0x18c/0x12f0 fs/block_dev.c:1474 blkdev_get fs/block_dev.c:1653 [inline] blkdev_get_by_path+0x25a/0x480 fs/block_dev.c:1690 mount_bdev+0x51/0x370 fs/super.c:1400 vfat_mount+0x34/0x40 fs/fat/namei_vfat.c:1057 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593 vfs_get_tree+0x88/0x290 fs/super.c:1572 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917 path_mount+0x56f/0xcb0 fs/namespace.c:3247 do_mount fs/namespace.c:3260 [inline] __do_sys_mount fs/namespace.c:3468 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3445 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f433ad9c169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f43393c4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f433afb5160 RCX: 00007f433ad9c169 RDX: 0000400000001200 RSI: 00004000000000c0 RDI: 00004000000001c0 RBP: 00007f433ae1d2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000f00 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f433afb5160 R15: 00007ffe28b546c8 Allocated by task 18479: 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+0xdb/0x110 mm/kasan/common.c:509 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1aa/0x330 mm/slub.c:4033 __kmalloc_node include/linux/slab.h:418 [inline] kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x82/0x130 mm/util.c:612 kvmalloc include/linux/mm.h:822 [inline] kvmalloc_array include/linux/mm.h:840 [inline] alloc_fdtable+0xcf/0x260 fs/file.c:132 dup_fd+0x7af/0xb30 fs/file.c:350 copy_files+0xe6/0x200 kernel/fork.c:1541 copy_process+0x10ac/0x3340 kernel/fork.c:2171 kernel_clone+0x21e/0x9e0 kernel/fork.c:2574 __do_sys_clone kernel/fork.c:2700 [inline] __se_sys_clone kernel/fork.c:2684 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2684 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 24744: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x121/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1595 [inline] slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc3/0x270 mm/slub.c:4191 skb_free_head net/core/skbuff.c:606 [inline] skb_release_data+0x5c6/0x6f0 net/core/skbuff.c:626 skb_release_all net/core/skbuff.c:680 [inline] __kfree_skb net/core/skbuff.c:694 [inline] consume_skb+0xac/0x250 net/core/skbuff.c:851 netlink_broadcast_filtered+0x114e/0x1270 net/netlink/af_netlink.c:1517 netlink_broadcast net/netlink/af_netlink.c:1539 [inline] nlmsg_multicast include/net/netlink.h:1033 [inline] nlmsg_notify+0x101/0x1c0 net/netlink/af_netlink.c:2528 rtnl_notify net/core/rtnetlink.c:737 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3865 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:3880 [inline] rtnetlink_event+0x15a/0x1b0 net/core/rtnetlink.c:5658 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] netdev_features_change+0x13b/0x1b0 net/core/dev.c:1465 netdev_update_features+0x33/0x40 net/core/dev.c:9784 veth_xdp_set drivers/net/veth.c:1203 [inline] veth_xdp+0x40a/0x590 drivers/net/veth.c:1216 dev_xdp_install+0x151/0x380 net/core/dev.c:9129 dev_xdp_attach+0x8ba/0xb30 net/core/dev.c:9267 dev_change_xdp_fd+0x1db/0x260 net/core/dev.c:9513 do_setlink+0x36bb/0x3c30 net/core/rtnetlink.c:2946 rtnl_group_changelink net/core/rtnetlink.c:3248 [inline] __rtnl_newlink net/core/rtnetlink.c:3417 [inline] rtnl_newlink+0x109a/0x2000 net/core/rtnetlink.c:3527 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5607 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2485 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5625 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline] netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1333 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2376 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg+0x1b1/0x280 net/socket.c:2466 __x64_sys_sendmsg+0x7b/0x90 net/socket.c:2466 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8881009a4000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1120 bytes inside of 2048-byte region [ffff8881009a4000, ffff8881009a4800) The buggy address belongs to the page: page:ffffea0004026800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1009a0 head:ffffea0004026800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042d80 raw: 0000000000000000 0000000000080008 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 1, ts 1853394943, 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+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348 allocate_slab mm/slub.c:1808 [inline] new_slab+0x80/0x400 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x302/0x4b0 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc_trace+0x1bd/0x2e0 mm/slub.c:2972 kmem_cache_alloc_node_trace include/linux/slab.h:440 [inline] kmalloc_node include/linux/slab.h:570 [inline] kzalloc_node include/linux/slab.h:675 [inline] __alloc_disk_node+0x76/0x570 block/genhd.c:1727 brd_alloc+0x146/0x400 drivers/block/brd.c:394 brd_init+0x125/0x474 drivers/block/brd.c:517 do_one_initcall+0x189/0x620 init/main.c:1197 do_initcall_level+0x186/0x304 init/main.c:1270 do_initcalls+0x4e/0x8e init/main.c:1286 do_basic_setup+0x88/0x91 init/main.c:1306 kernel_init_freeable+0x2be/0x3f5 init/main.c:1510 kernel_init+0x11/0x280 init/main.c:1397 page_owner free stack trace missing Memory state around the buggy address: ffff8881009a4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881009a4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881009a4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881009a4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881009a4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== incfs: Error accessing: ./file0. incfs: mount failed -20