Vulnerability CVE-2024-26615

Vulnerability CVE-2024-26615

Published: 2024-03-11

Description:

In the Linux kernel, the following vulnerability has been resolved:

net/smc: fix illegal rmb_desc access in SMC-D connection dump

A crash was found when dumping SMC-D connections. It can be reproduced
by following steps:

- run nginx/wrk test:
smc_run nginx
smc_run wrk -t 16 -c 1000 -d <duration> -H 'Connection: Close' <URL>

- continuously dump SMC-D connections in parallel:
watch -n 1 'smcss -D'

BUG: kernel NULL pointer dereference, address: 0000000000000030
CPU: 2 PID: 7204 Comm: smcss Kdump: loaded Tainted: G E 6.7.0+ #55
RIP: 0010:__smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]
Call Trace:
<TASK>
? __die+0x24/0x70
? page_fault_oops+0x66/0x150
? exc_page_fault+0x69/0x140
? asm_exc_page_fault+0x26/0x30
? __smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]
? __kmalloc_node_track_caller+0x35d/0x430
? __alloc_skb+0x77/0x170
smc_diag_dump_proto+0xd0/0xf0 [smc_diag]
smc_diag_dump+0x26/0x60 [smc_diag]
netlink_dump+0x19f/0x320
__netlink_dump_start+0x1dc/0x300
smc_diag_handler_dump+0x6a/0x80 [smc_diag]
? __pfx_smc_diag_dump+0x10/0x10 [smc_diag]
sock_diag_rcv_msg+0x121/0x140
? __pfx_sock_diag_rcv_msg+0x10/0x10
netlink_rcv_skb+0x5a/0x110
sock_diag_rcv+0x28/0x40
netlink_unicast+0x22a/0x330
netlink_sendmsg+0x1f8/0x420
__sock_sendmsg+0xb0/0xc0
____sys_sendmsg+0x24e/0x300
? copy_msghdr_from_user+0x62/0x80
___sys_sendmsg+0x7c/0xd0
? __do_fault+0x34/0x160
? do_read_fault+0x5f/0x100
? do_fault+0xb0/0x110
? __handle_mm_fault+0x2b0/0x6c0
__sys_sendmsg+0x4d/0x80
do_syscall_64+0x69/0x180
entry_SYSCALL_64_after_hwframe+0x6e/0x76

It is possible that the connection is in process of being established
when we dump it. Assumed that the connection has been registered in a
link group by smc_conn_create() but the rmb_desc has not yet been
initialized by smc_buf_create(), thus causing the illegal access to
conn->rmb_desc. So fix it by checking before dump.

References:

https://git.kernel.org/stable/c/27aea64838914c6122db5b8bd4bed865c9736f22

https://git.kernel.org/stable/c/1fea9969b81c67d0cb1611d1b8b7d19049d937be

https://git.kernel.org/stable/c/5fed92ca32eafbfae8b6bee8ca34cca71c6a8b6d

https://git.kernel.org/stable/c/68b888d51ac82f2b96bf5e077a31d76afcdef25a

https://git.kernel.org/stable/c/6994dba06321e3c48fdad0ba796a063d9d82183a

https://git.kernel.org/stable/c/a164c2922675d7051805cdaf2b07daffe44f20d9

https://git.kernel.org/stable/c/8f3f9186e5bb96a9c9654c41653210e3ea7e48a6

https://git.kernel.org/stable/c/dbc153fd3c142909e564bb256da087e13fbf239c

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