Hello, syzbot found the following issue on: HEAD commit: 787af64d05cd mm: page_alloc: validate buddy before check i.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16b1ebf5700000 kernel config: https://syzkaller.appspot.com/x/.config?x=84cc605575ae78ef dashboard link: https://syzkaller.appspot.com/bug?extid=eabbf2aaa999cc507108 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+eabbf2aaa999cc507108@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in cdc_ncm_set_dgram_size+0xc91/0xde0 drivers/net/usb/cdc_ncm.c:608 Read of size 8 at addr ffff8880755210b0 by task dhcpcd/3174 CPU: 0 PID: 3174 Comm: dhcpcd Tainted: G W 5.17.0-syzkaller-13430-g787af64d05cd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 cdc_ncm_set_dgram_size+0xc91/0xde0 drivers/net/usb/cdc_ncm.c:608 cdc_ncm_change_mtu+0x10c/0x140 drivers/net/usb/cdc_ncm.c:798 __dev_set_mtu net/core/dev.c:8519 [inline] dev_set_mtu_ext+0x352/0x5b0 net/core/dev.c:8572 dev_set_mtu+0x8e/0x120 net/core/dev.c:8596 dev_ifsioc+0xb87/0x1090 net/core/dev_ioctl.c:332 dev_ioctl+0x1b9/0xe30 net/core/dev_ioctl.c:586 sock_do_ioctl+0x15a/0x230 net/socket.c:1136 sock_ioctl+0x2f1/0x640 net/socket.c:1239 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f00859e70e7 Code: 3c 1c e8 1c ff ff ff 85 c0 79 87 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 61 9d 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffedd503dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f00858f96c8 RCX: 00007f00859e70e7 RDX: 00007ffedd513fc8 RSI: 0000000000008922 RDI: 0000000000000018 RBP: 00007ffedd524178 R08: 00007ffedd513f88 R09: 00007ffedd513f38 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffedd513fc8 R14: 0000000000000028 R15: 0000000000008922 </TASK> Allocated by task 26: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:714 [inline] cdc_ncm_bind_common+0xb8/0x2df0 drivers/net/usb/cdc_ncm.c:826 cdc_ncm_bind+0x7c/0x1c0 drivers/net/usb/cdc_ncm.c:1069 usbnet_probe+0xaf8/0x2580 drivers/net/usb/usbnet.c:1747 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:541 [inline] really_probe+0x23e/0xb20 drivers/base/dd.c:620 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:751 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:781 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:898 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x228/0x4a0 drivers/base/dd.c:969 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xb83/0x1e20 drivers/base/core.c:3405 usb_set_configuration+0x101e/0x1900 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238 usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:541 [inline] really_probe+0x23e/0xb20 drivers/base/dd.c:620 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:751 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:781 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:898 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x228/0x4a0 drivers/base/dd.c:969 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xb83/0x1e20 drivers/base/core.c:3405 usb_new_device.cold+0x641/0x1091 drivers/usb/core/hub.c:2566 hub_port_connect drivers/usb/core/hub.c:5363 [inline] hub_port_connect_change drivers/usb/core/hub.c:5507 [inline] port_event drivers/usb/core/hub.c:5665 [inline] hub_event+0x25c6/0x4680 drivers/usb/core/hub.c:5747 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Freed by task 3742: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3510 [inline] kfree+0xd6/0x4d0 mm/slub.c:4552 cdc_ncm_free+0x145/0x1a0 drivers/net/usb/cdc_ncm.c:786 cdc_ncm_unbind+0x1a7/0x340 drivers/net/usb/cdc_ncm.c:1021 usbnet_disconnect+0x103/0x270 drivers/net/usb/usbnet.c:1620 usb_unbind_interface+0x1d8/0x8e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:531 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:523 __device_release_driver drivers/base/dd.c:1199 [inline] device_release_driver_internal+0x4a3/0x680 drivers/base/dd.c:1222 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529 device_del+0x4f3/0xc80 drivers/base/core.c:3592 usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1419 usb_disconnect.cold+0x278/0x6ec drivers/usb/core/hub.c:2228 hub_port_connect drivers/usb/core/hub.c:5207 [inline] hub_port_connect_change drivers/usb/core/hub.c:5507 [inline] port_event drivers/usb/core/hub.c:5665 [inline] hub_event+0x1e74/0x4680 drivers/usb/core/hub.c:5747 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff888075521000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 176 bytes inside of 512-byte region [ffff888075521000, ffff888075521200) The buggy address belongs to the physical page: page:ffffea0001d54800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888075522800 pfn:0x75520 head:ffffea0001d54800 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001f37f08 ffffea0001d16d08 ffff888010c41c80 raw: ffff888075522800 0000000000100007 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 21, tgid 21 (ksoftirqd/1), ts 65372771303, free_ts 55099250438 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3df0 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2262 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] __kmalloc_node_track_caller+0x2cb/0x360 mm/slub.c:4947 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 __napi_alloc_skb+0x70/0x310 net/core/skbuff.c:568 napi_alloc_skb include/linux/skbuff.h:3157 [inline] page_to_skb+0x188/0xc00 drivers/net/virtio_net.c:437 receive_mergeable drivers/net/virtio_net.c:1039 [inline] receive_buf+0xd24/0x5210 drivers/net/virtio_net.c:1149 virtnet_receive drivers/net/virtio_net.c:1441 [inline] virtnet_poll+0x5cd/0x11a0 drivers/net/virtio_net.c:1550 __napi_poll+0xb3/0x6e0 net/core/dev.c:6413 napi_poll net/core/dev.c:6480 [inline] net_rx_action+0x8ec/0xc60 net/core/dev.c:6567 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3423 __put_page+0x17d/0x280 mm/swap.c:127 folio_put include/linux/mm.h:1200 [inline] put_page include/linux/mm.h:1233 [inline] __skb_frag_unref include/linux/skbuff.h:3330 [inline] skb_release_data+0x513/0x810 net/core/skbuff.c:672 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb+0x46/0x60 net/core/skbuff.c:756 __sk_defer_free_flush net/ipv4/tcp.c:1601 [inline] sk_defer_free_flush include/net/tcp.h:1380 [inline] tcp_recvmsg+0x1ca/0x610 net/ipv4/tcp.c:2577 inet_recvmsg+0x11b/0x5e0 net/ipv4/af_inet.c:850 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] sock_recvmsg net/socket.c:962 [inline] sock_read_iter+0x336/0x470 net/socket.c:1039 call_read_iter include/linux/fs.h:2073 [inline] new_sync_read+0x4f9/0x5f0 fs/read_write.c:401 vfs_read+0x492/0x5d0 fs/read_write.c:482 ksys_read+0x1e8/0x250 fs/read_write.c:620 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888075520f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888075521000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888075521080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888075521100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075521180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. 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