syzbot

 sign-in | mailing list | source | docs
🐞 Open [1455]
≡ Subsystems
🐞 Fixed [6881]
🐞 Invalid [17882]
⬇ Missing Backports [224]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

KASAN: use-after-free Read in __ethtool_get_link_ksettings

Status: auto-closed as invalid on 2022/07/07 00:01
Subsystems: net
[Documentation on labels]
First crash: 1425d, last: 1389d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in __ethtool_get_link_ksettings 19 7 488d 622d 0/3 auto-obsoleted due to no activity on 2025/01/02 21:40
upstream KASAN: use-after-free Read in __ethtool_get_link_ksettings (2) net 19 1 1283d 1278d 0/29 auto-obsoleted due to no activity on 2022/11/20 15:32
upstream KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings rdma 19 syz done 23038 10m 674d 0/29 upstream: reported syz repro on 2024/03/22 20:10
linux-6.6 KASAN: slab-use-after-free Read in __ethtool_get_link_ksettings 19 1 212d 212d 0/2 auto-obsoleted due to no activity on 2025/10/05 22:34
upstream general protection fault in __ethtool_get_link_ksettings net 7 C error unreliable 298 1657d 1816d 0/29 closed as invalid on 2021/10/06 01:39

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __ethtool_get_link_ksettings+0x162/0x180 net/ethtool/ioctl.c:457
Read of size 8 at addr ffff888075a7e208 by task kworker/0:6/5568

CPU: 0 PID: 5568 Comm: kworker/0:6 Not tainted 5.18.0-rc1-syzkaller-00037-g42e7a03d3bad #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events smc_ib_port_event_work
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
 __ethtool_get_link_ksettings+0x162/0x180 net/ethtool/ioctl.c:457
 __ethtool_get_link_ksettings+0xeb/0x180 net/ethtool/ioctl.c:461
 ib_get_eth_speed+0x10b/0x600 drivers/infiniband/core/verbs.c:1896
 rxe_query_port+0x13c/0x2d0 drivers/infiniband/sw/rxe/rxe_verbs.c:38
 __ib_query_port drivers/infiniband/core/device.c:2059 [inline]
 ib_query_port drivers/infiniband/core/device.c:2091 [inline]
 ib_query_port+0x42b/0x8a0 drivers/infiniband/core/device.c:2081
 smc_ib_remember_port_attr net/smc/smc_ib.c:358 [inline]
 smc_ib_port_event_work+0x14e/0xc30 net/smc/smc_ib.c:382
 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
 </TASK>

Allocated by task 3619:
 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_node include/linux/slab.h:604 [inline]
 kvmalloc_node+0x3e/0x130 mm/util.c:580
 kvmalloc include/linux/slab.h:731 [inline]
 kvzalloc include/linux/slab.h:739 [inline]
 alloc_netdev_mqs+0x98/0x1100 net/core/dev.c:10495
 rtnl_create_link+0x9d7/0xc00 net/core/rtnetlink.c:3204
 __rtnl_newlink+0xf85/0x1760 net/core/rtnetlink.c:3473
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3531
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5990
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 __sys_sendto+0x216/0x310 net/socket.c:2040
 __do_sys_sendto net/socket.c:2052 [inline]
 __se_sys_sendto net/socket.c:2048 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 5892:
 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
 kvfree+0x42/0x50 mm/util.c:615
 device_release+0x9f/0x240 drivers/base/core.c:2229
 kobject_cleanup lib/kobject.c:705 [inline]
 kobject_release lib/kobject.c:736 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1c8/0x540 lib/kobject.c:753
 netdev_run_todo+0x72e/0x10b0 net/core/dev.c:10274
 rtnl_unlock net/core/rtnetlink.c:112 [inline]
 rtnetlink_rcv_msg+0x420/0xb80 net/core/rtnetlink.c:5991
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888075a7e000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 520 bytes inside of
 4096-byte region [ffff888075a7e000, ffff888075a7f000)

The buggy address belongs to the physical page:
page:ffffea0001d69e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75a78
head:ffffea0001d69e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010c4c280
raw: 0000000000000000 0000000000040004 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 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3621, tgid 3621 (syz-executor.2), ts 103918448883, free_ts 98178811554
 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+0x2cb/0x390 mm/slub.c:4458
 kmalloc_node include/linux/slab.h:604 [inline]
 kvmalloc_node+0x3e/0x130 mm/util.c:580
 kvmalloc include/linux/slab.h:731 [inline]
 kvzalloc include/linux/slab.h:739 [inline]
 alloc_netdev_mqs+0x98/0x1100 net/core/dev.c:10495
 rtnl_create_link+0x9d7/0xc00 net/core/rtnetlink.c:3204
 veth_newlink+0x20e/0xa90 drivers/net/veth.c:1748
 __rtnl_newlink+0x107f/0x1760 net/core/rtnetlink.c:3483
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3531
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5990
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
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
 tcp_eat_recv_skb+0x1ed/0x280 net/ipv4/tcp.c:1619
 tcp_recvmsg_locked+0x105c/0x1fd0 net/ipv4/tcp.c:2528
 tcp_recvmsg+0x137/0x610 net/ipv4/tcp.c:2574
 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:2044 [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+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff888075a7e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888075a7e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888075a7e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888075a7e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888075a7e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/04/07 23:54 upstream 42e7a03d3bad c6ff3e05 .config console log report info ci-upstream-kasan-gce-root KASAN: use-after-free Read in __ethtool_get_link_ksettings
2022/03/02 18:49 net-next-old a577223a97df 45a13a73 .config console log report info ci-upstream-net-kasan-gce KASAN: use-after-free Read in __ethtool_get_link_ksettings
* Struck through repros no longer work on HEAD.