[syzbot] KASAN: use-after-free Read in addr_handler (4)

From: syzbot
Date: Wed Sep 15 2021 - 08:41:25 EST


Hello,

syzbot found the following issue on:

HEAD commit: 926de8c4326c Merge tag 'acpi-5.15-rc1-3' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11fd67ed300000
kernel config: https://syzkaller.appspot.com/x/.config?x=37df9ef5660a8387
dashboard link: https://syzkaller.appspot.com/bug?extid=dc3dfba010d7671e05f5
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1

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+dc3dfba010d7671e05f5@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:575 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0x105b/0x12f0 kernel/locking/mutex.c:729
Read of size 8 at addr ffff88803991f3b0 by task kworker/u4:3/158

CPU: 0 PID: 158 Comm: kworker/u4:3 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ib_addr process_one_req
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:256
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
__mutex_lock_common kernel/locking/mutex.c:575 [inline]
__mutex_lock+0x105b/0x12f0 kernel/locking/mutex.c:729
addr_handler+0xac/0x470 drivers/infiniband/core/cma.c:3247
process_one_req+0xfa/0x680 drivers/infiniband/core/addr.c:647
process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297
worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Allocated by task 2916:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
____kasan_kmalloc mm/kasan/common.c:472 [inline]
__kasan_kmalloc+0xa4/0xd0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
__rdma_create_id+0x5b/0x550 drivers/infiniband/core/cma.c:839
rdma_create_user_id+0x79/0xd0 drivers/infiniband/core/cma.c:893
ucma_create_id+0x162/0x360 drivers/infiniband/core/ucma.c:461
ucma_write+0x25c/0x350 drivers/infiniband/core/ucma.c:1732
vfs_write+0x28e/0xae0 fs/read_write.c:592
ksys_write+0x1ee/0x250 fs/read_write.c:647
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 2916:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1700 [inline]
slab_free_freelist_hook+0x81/0x190 mm/slub.c:1725
slab_free mm/slub.c:3483 [inline]
kfree+0xe4/0x530 mm/slub.c:4543
ucma_close_id drivers/infiniband/core/ucma.c:185 [inline]
ucma_destroy_private_ctx+0x8b3/0xb70 drivers/infiniband/core/ucma.c:576
ucma_destroy_id+0x1e6/0x280 drivers/infiniband/core/ucma.c:614
ucma_write+0x25c/0x350 drivers/infiniband/core/ucma.c:1732
vfs_write+0x28e/0xae0 fs/read_write.c:592
ksys_write+0x1ee/0x250 fs/read_write.c:647
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

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe9/0x110 mm/kasan/generic.c:348
__call_rcu kernel/rcu/tree.c:2987 [inline]
call_rcu+0xb1/0x750 kernel/rcu/tree.c:3067
netlink_release+0xdd4/0x1dd0 net/netlink/af_netlink.c:812
__sock_release+0xcd/0x280 net/socket.c:649
sock_close+0x18/0x20 net/socket.c:1314
__fput+0x288/0x9f0 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
exit_task_work include/linux/task_work.h:32 [inline]
do_exit+0xbae/0x2a30 kernel/exit.c:825
do_group_exit+0x125/0x310 kernel/exit.c:922
__do_sys_exit_group kernel/exit.c:933 [inline]
__se_sys_exit_group kernel/exit.c:931 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
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 ffff88803991f000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 944 bytes inside of
2048-byte region [ffff88803991f000, ffff88803991f800)
The buggy address belongs to the page:
page:ffffea0000e64600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x39918
head:ffffea0000e64600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c42000
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 6632, ts 274175306325, free_ts 0
prep_new_page mm/page_alloc.c:2424 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4153
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5375
alloc_pages+0x1a7/0x300 mm/mempolicy.c:2197
alloc_slab_page mm/slub.c:1763 [inline]
allocate_slab mm/slub.c:1900 [inline]
new_slab+0x319/0x490 mm/slub.c:1963
___slab_alloc+0x921/0xfe0 mm/slub.c:2994
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3081
slab_alloc_node mm/slub.c:3172 [inline]
slab_alloc mm/slub.c:3214 [inline]
__kmalloc+0x305/0x320 mm/slub.c:4387
kmalloc_array include/linux/slab.h:631 [inline]
kcalloc include/linux/slab.h:660 [inline]
veth_alloc_queues drivers/net/veth.c:1314 [inline]
veth_dev_init+0x114/0x2e0 drivers/net/veth.c:1341
register_netdevice+0x51e/0x1500 net/core/dev.c:10225
veth_newlink+0x58c/0xb20 drivers/net/veth.c:1726
__rtnl_newlink+0x106d/0x1750 net/core/rtnetlink.c:3458
rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3506
rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
page_owner free stack trace missing

Memory state around the buggy address:
ffff88803991f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803991f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803991f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88803991f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803991f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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