Vulnerability CVE-2024-46735

Vulnerability CVE-2024-46735

Published: 2024-09-18

Description:

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

ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery()

When two UBLK_CMD_START_USER_RECOVERY commands are submitted, the
first one sets 'ubq->ubq_daemon' to NULL, and the second one triggers
WARN in ublk_queue_reinit() and subsequently a NULL pointer dereference
issue.

Fix it by adding the check in ublk_ctrl_start_recovery() and return
immediately in case of zero 'ub->nr_queues_ready'.

BUG: kernel NULL pointer dereference, address: 0000000000000028
RIP: 0010:ublk_ctrl_start_recovery.constprop.0+0x82/0x180
Call Trace:
<TASK>
? __die+0x20/0x70
? page_fault_oops+0x75/0x170
? exc_page_fault+0x64/0x140
? asm_exc_page_fault+0x22/0x30
? ublk_ctrl_start_recovery.constprop.0+0x82/0x180
ublk_ctrl_uring_cmd+0x4f7/0x6c0
? pick_next_task_idle+0x26/0x40
io_uring_cmd+0x9a/0x1b0
io_issue_sqe+0x193/0x3f0
io_wq_submit_work+0x9b/0x390
io_worker_handle_work+0x165/0x360
io_wq_worker+0xcb/0x2f0
? finish_task_switch.isra.0+0x203/0x290
? finish_task_switch.isra.0+0x203/0x290
? __pfx_io_wq_worker+0x10/0x10
ret_from_fork+0x2d/0x50
? __pfx_io_wq_worker+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>

References:

https://git.kernel.org/stable/c/ca249435893dda766f3845c15ca77ca5672022d8

https://git.kernel.org/stable/c/136a29d8112df4ea0a57f9602ddf3579e04089dc

https://git.kernel.org/stable/c/7c890ef60bf417d3fe5c6f7a9f6cef0e1d77f74f

https://git.kernel.org/stable/c/e58f5142f88320a5b1449f96a146f2f24615c5c7

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