CVE-2021-47375
"Linux Kernel blktrace: Use-After-Free Vulnerability"
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.
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
April 2, 2025, 2:53 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
2.5
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47375.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47375 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47375 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 02, 2025
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.14.9 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.70 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.150 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 4.19.209 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.30 up to (excluding) 4.4.286 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.5 up to (excluding) 4.9.285 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.10 up to (excluding) 4.14.249 Added Reference Type CVE: https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069 Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee Added Reference https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5 Added Reference https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 Added Reference https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222 Added Reference https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26 Added Reference https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40 Added Reference https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269 Added Reference https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 27, 2024
Action Type Old Value New Value Added CWE CISA-ADP CWE-416 Added CVSS V3.1 CISA-ADP AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added 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. Added Reference kernel.org https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47375 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47375
weaknesses.