Hi, 01.03.2018, 11:46, "syzbot" <syzbot+70ce058e01259de7bb1d@xxxxxxxxxxxxxxxxxxxxxxxxx>: > Hello, > > syzbot hit the following crash on upstream commit > f3afe530d644488a074291da04a69a296ab63046 (Tue Feb 27 22:02:39 2018 +0000) > Merge branch 'fixes-v4.16-rc4' of > git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security > > So far this crash happened 4 times on upstream. > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+70ce058e01259de7bb1d@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > ================================================================== > BUG: KASAN: use-after-free in strlen+0x85/0xa0 lib/string.c:482 > Read of size 1 at addr ffff8801d6c38f40 by task kworker/0:1/23 > > CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 4.16.0-rc3+ #332 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: hwsim_wq destroy_radio > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x24d lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report+0x23b/0x360 mm/kasan/report.c:412 > __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 > strlen+0x85/0xa0 lib/string.c:482 > strlen include/linux/string.h:267 [inline] > hwsim_mcast_del_radio drivers/net/wireless/mac80211_hwsim.c:2835 [inline] > mac80211_hwsim_del_radio+0x168/0x3b0 > drivers/net/wireless/mac80211_hwsim.c:2854 > destroy_radio+0x9d/0x100 drivers/net/wireless/mac80211_hwsim.c:3396 > process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 > worker_thread+0x223/0x1990 kernel/workqueue.c:2247 > kthread+0x33c/0x400 kernel/kthread.c:238 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 > > Allocated by task 6226: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552 > __do_kmalloc mm/slab.c:3705 [inline] > __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3720 > kvasprintf+0xa9/0x130 lib/kasprintf.c:25 > kvasprintf_const+0x56/0x160 lib/kasprintf.c:49 > kobject_set_name_vargs+0x5b/0x140 lib/kobject.c:263 > dev_set_name+0xb4/0xf0 drivers/base/core.c:1649 > wiphy_new_nm+0x910/0x21d0 net/wireless/core.c:451 > ieee80211_alloc_hw_nm+0x4b4/0x2180 net/mac80211/main.c:531 > mac80211_hwsim_new_radio+0x227/0x2cd0 > drivers/net/wireless/mac80211_hwsim.c:2537 > hwsim_new_radio_nl+0x67a/0x8c0 drivers/net/wireless/mac80211_hwsim.c:3213 > genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:599 > genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:624 > netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2444 > genl_rcv+0x28/0x40 net/netlink/genetlink.c:635 > netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline] > netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334 > netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897 > sock_sendmsg_nosec net/socket.c:630 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:640 > ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 > __sys_sendmsg+0xe5/0x210 net/socket.c:2080 > SYSC_sendmsg net/socket.c:2091 [inline] > SyS_sendmsg+0x2d/0x50 net/socket.c:2087 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > Freed by task 5: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 > __cache_free mm/slab.c:3485 [inline] > kfree+0xd9/0x260 mm/slab.c:3800 > kfree_const+0x31/0x40 mm/util.c:38 > kobject_rename+0x1b3/0x2a0 lib/kobject.c:501 > device_rename+0x147/0x1f0 drivers/base/core.c:2648 > cfg80211_switch_netns+0x1fa/0x470 net/wireless/core.c:192 > cfg80211_pernet_exit+0x93/0xc0 net/wireless/core.c:1336 > ops_exit_list.isra.6+0xae/0x150 net/core/net_namespace.c:142 > cleanup_net+0x6a1/0xcb0 net/core/net_namespace.c:517 > process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 > worker_thread+0x223/0x1990 kernel/workqueue.c:2247 > kthread+0x33c/0x400 kernel/kthread.c:238 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 > > The buggy address belongs to the object at ffff8801d6c38f40 > which belongs to the cache kmalloc-32 of size 32 > The buggy address is located 0 bytes inside of > 32-byte region [ffff8801d6c38f40, ffff8801d6c38f60) > The buggy address belongs to the page: > page:ffffea00075b0e00 count:1 mapcount:0 mapping:ffff8801d6c38000 > index:0xffff8801d6c38fc1 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffff8801d6c38000 ffff8801d6c38fc1 000000010000003f > raw: ffffea00075b0c20 ffffea00075b0f20 ffff8801dac001c0 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d6c38e00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ffff8801d6c38e80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >> ffff8801d6c38f00: 07 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc > > ^ > ffff8801d6c38f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d6c39000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ================================================================== > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body. JFI: As a coincidence, I'm converting pernet_operation and hwsim_net_ops are the last in drivers directory which is not converted. There is also an issue with hwsim_netgroup, and I sent a fix today: https://patchwork.ozlabs.org/patch/879748/ Thanks, Kirill
