zram: fix NULL pointer in comp_algorithm_show()
LTP reported a NULL pointer dereference as followed:
CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __pi_strcmp+0x24/0x140
lr : zcomp_available_show+0x60/0x100 [zram]
sp : ffff800088b93b90
x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0
x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000
x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280
x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c
x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000
Call trace:
__pi_strcmp+0x24/0x140
comp_algorithm_show+0x40/0x70 [zram]
dev_attr_show+0x28/0x80
sysfs_kf_seq_show+0x90/0x140
kernfs_seq_show+0x34/0x48
seq_read_iter+0x1d4/0x4e8
kernfs_fop_read_iter+0x40/0x58
new_sync_read+0x9c/0x168
vfs_read+0x1a8/0x1f8
ksys_read+0x74/0x108
__arm64_sys_read+0x24/0x38
invoke_syscall+0x50/0x120
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x38/0x138
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x188/0x190
The zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if
comp_algorithm_set() has not been called. User can access the zram device
by sysfs after device_add_disk(), so there is a time window to trigger the
NULL pointer dereference. Move it ahead device_add_disk() to make sure
when user can access the zram device, it is ready. comp_algorithm_set()
is protected by zram->init_lock in other places and no such problem.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2024-51894 | In the Linux kernel, the following vulnerability has been resolved: zram: fix NULL pointer in comp_algorithm_show() LTP reported a NULL pointer dereference as followed: CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __pi_strcmp+0x24/0x140 lr : zcomp_available_show+0x60/0x100 [zram] sp : ffff800088b93b90 x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0 x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000 x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280 x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000 Call trace: __pi_strcmp+0x24/0x140 comp_algorithm_show+0x40/0x70 [zram] dev_attr_show+0x28/0x80 sysfs_kf_seq_show+0x90/0x140 kernfs_seq_show+0x34/0x48 seq_read_iter+0x1d4/0x4e8 kernfs_fop_read_iter+0x40/0x58 new_sync_read+0x9c/0x168 vfs_read+0x1a8/0x1f8 ksys_read+0x74/0x108 __arm64_sys_read+0x24/0x38 invoke_syscall+0x50/0x120 el0_svc_common.constprop.0+0xc8/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x38/0x138 el0t_64_sync_handler+0xc0/0xc8 el0t_64_sync+0x188/0x190 The zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if comp_algorithm_set() has not been called. User can access the zram device by sysfs after device_add_disk(), so there is a time window to trigger the NULL pointer dereference. Move it ahead device_add_disk() to make sure when user can access the zram device, it is ready. comp_algorithm_set() is protected by zram->init_lock in other places and no such problem. |
Ubuntu USN |
USN-7449-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7449-2 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7450-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7451-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7452-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7453-1 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7468-1 | Linux kernel (Azure, N-Series) vulnerabilities |
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USN-7523-1 | Linux kernel (Raspberry Pi Real-time) vulnerabilities |
Ubuntu USN |
USN-7524-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7605-1 | Linux kernel vulnerabilities |
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USN-7605-2 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-7606-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-7628-1 | Linux kernel (Azure) vulnerabilities |
Wed, 16 Jul 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
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epss
|
Wed, 14 May 2025 02:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux |
Mon, 24 Mar 2025 15:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 08 Jan 2025 21:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-476 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
Mon, 30 Dec 2024 01:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 27 Dec 2024 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: zram: fix NULL pointer in comp_algorithm_show() LTP reported a NULL pointer dereference as followed: CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __pi_strcmp+0x24/0x140 lr : zcomp_available_show+0x60/0x100 [zram] sp : ffff800088b93b90 x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0 x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000 x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280 x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000 Call trace: __pi_strcmp+0x24/0x140 comp_algorithm_show+0x40/0x70 [zram] dev_attr_show+0x28/0x80 sysfs_kf_seq_show+0x90/0x140 kernfs_seq_show+0x34/0x48 seq_read_iter+0x1d4/0x4e8 kernfs_fop_read_iter+0x40/0x58 new_sync_read+0x9c/0x168 vfs_read+0x1a8/0x1f8 ksys_read+0x74/0x108 __arm64_sys_read+0x24/0x38 invoke_syscall+0x50/0x120 el0_svc_common.constprop.0+0xc8/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x38/0x138 el0t_64_sync_handler+0xc0/0xc8 el0t_64_sync+0x188/0x190 The zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if comp_algorithm_set() has not been called. User can access the zram device by sysfs after device_add_disk(), so there is a time window to trigger the NULL pointer dereference. Move it ahead device_add_disk() to make sure when user can access the zram device, it is ready. comp_algorithm_set() is protected by zram->init_lock in other places and no such problem. | |
| Title | zram: fix NULL pointer in comp_algorithm_show() | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T20:53:12.493Z
Reserved: 2024-11-19T17:17:25.024Z
Link: CVE-2024-53222
No data.
Status : Modified
Published: 2024-12-27T14:15:30.327
Modified: 2025-03-24T16:15:19.853
Link: CVE-2024-53222
OpenCVE Enrichment
No data.
EUVD
Ubuntu USN