Description

In the Linux kernel, the following vulnerability has been resolved: blktrace: Fix uaf in blk_trace access after removing by sysfs There is an use-after-free problem triggered by following process: P1(sda) P2(sdb) echo 0 > /sys/block/sdb/trace/enable blk_trace_remove_queue synchronize_rcu blk_trace_free relay_close rcu_read_lock __blk_add_trace trace_note_tsk (Iterate running_trace_list) relay_close_buf relay_destroy_buf kfree(buf) trace_note(sdb's bt) relay_reserve buf->offset <- nullptr deference (use-after-free) !!! rcu_read_unlock [ 502.714379] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 502.715260] #PF: supervisor read access in kernel mode [ 502.715903] #PF: error_code(0x0000) - not-present page [ 502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0 [ 502.717252] Oops: 0000 [#1] SMP [ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360 [ 502.732872] Call Trace: [ 502.733193] __blk_add_trace.cold+0x137/0x1a3 [ 502.733734] blk_add_trace_rq+0x7b/0xd0 [ 502.734207] blk_add_trace_rq_issue+0x54/0xa0 [ 502.734755] blk_mq_start_request+0xde/0x1b0 [ 502.735287] scsi_queue_rq+0x528/0x1140 ... [ 502.742704] sg_new_write.isra.0+0x16e/0x3e0 [ 502.747501] sg_ioctl+0x466/0x1100 Reproduce method: ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sda, BLKTRACESTART) ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sdb, BLKTRACESTART) echo 0 > /sys/block/sdb/trace/enable & // Add delay(mdelay/msleep) before kernel enters blk_trace_free() ioctl$SG_IO(/dev/sda, SG_IO, ...) // Enters trace_note_tsk() after blk_trace_free() returned // Use mdelay in rcu region rather than msleep(which may schedule out) Remove blk_trace from running_list before calling blk_trace_free() by sysfs if blk_trace is at Blktrace_running state.

Metrics

 

CVSS Version 4.0 CVSS Version 3.x CVSS Version 2.0

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.

CVSS 4.0 Severity and Vector Strings:

NIST: NVD

N/A

NVD assessment not yet provided.

CVSS 3.x Severity and Vector Strings:

NIST: NVD

Base Score:  N/A

NVD assessment not yet provided.

ADP:  CISA-ADP

Base Score:  6.2 MEDIUM

Vector:  CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS 2.0 Severity and Vector Strings:

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee

https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5

https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9

https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222

https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26

https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40

https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269

https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069

CISA-ADP AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CISA-ADP CWE-416

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

blktrace: Fix uaf in blk_trace access after removing by sysfs

There is an use-after-free problem triggered by following process:

      P1(sda)				P2(sdb)
			echo 0 > /sys/block/sdb/trace/enable
			  blk_trace_remove_queue
			    synchronize_rcu
			    blk_trace_free
			      relay_close
rcu_read_lock
__blk_add_trace
  trace_note_tsk
  (Iterate running_trace_list)
			        relay_close_buf
				  relay_destroy_buf
				    kfre

kernel.org https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee [No types assigned]

kernel.org https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5 [No types assigned]

kernel.org https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 [No types assigned]

kernel.org https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222 [No types assigned]

kernel.org https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26 [No types assigned]

kernel.org https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40 [No types assigned]

kernel.org https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269 [No types assigned]

kernel.org https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069 [No types assigned]