CVE-2024-53222: zram: fix NULL pointer in comp_algorithm_show()
Vulnerability summary
CVE-2024-53222 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 13% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 23 · Related 21Timeline
- 27-12-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.22%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.22% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu106 products
- linux< 6.8.0-58.60
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1027.29
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 7ac07a26dea79c3892436bce41cce03dcbd3c4c7, < c7ee791e538537b281f60945298796f0a3971bbd | ≥ 7ac07a26dea79c3892436bce41cce03dcbd3c4c7, < 843d366ff19708668d95cda16bb8aba109a93dba | ≥ 7ac07a26dea79c3892436bce41cce03dcbd3c4c7, < f364cdeb38938f9d03061682b8ff3779dd1730e5 | 6.2
- linux_kernel≥ 6.2, < 6.12.2
Debian1 product
- linux< 6.12.3-1
3 vendors · 109 products
