{"id":"CVE-2024-53222","state":"PUBLISHED","title":"zram: fix NULL pointer in comp_algorithm_show()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nzram: fix NULL pointer in comp_algorithm_show()\n\nLTP reported a NULL pointer dereference as followed:\n\n CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3\n Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015\n pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n pc : __pi_strcmp+0x24/0x140\n lr : zcomp_available_show+0x60/0x100 [zram]\n sp : ffff800088b93b90\n x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0\n x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000\n x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900\n x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000\n x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000\n x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000\n x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280\n x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000\n x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c\n x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000\n Call trace:\n  __pi_strcmp+0x24/0x140\n  comp_algorithm_show+0x40/0x70 [zram]\n  dev_attr_show+0x28/0x80\n  sysfs_kf_seq_show+0x90/0x140\n  kernfs_seq_show+0x34/0x48\n  seq_read_iter+0x1d4/0x4e8\n  kernfs_fop_read_iter+0x40/0x58\n  new_sync_read+0x9c/0x168\n  vfs_read+0x1a8/0x1f8\n  ksys_read+0x74/0x108\n  __arm64_sys_read+0x24/0x38\n  invoke_syscall+0x50/0x120\n  el0_svc_common.constprop.0+0xc8/0xf0\n  do_el0_svc+0x24/0x38\n  el0_svc+0x38/0x138\n  el0t_64_sync_handler+0xc0/0xc8\n  el0t_64_sync+0x188/0x190\n\nThe zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if\ncomp_algorithm_set() has not been called.  User can access the zram device\nby sysfs after device_add_disk(), so there is a time window to trigger the\nNULL pointer dereference.  Move it ahead device_add_disk() to make sure\nwhen user can access the zram device, it is ready.  comp_algorithm_set()\nis protected by zram->init_lock in other places and no such problem.","publishedAt":"2024-12-27T13:50:12.652Z","updatedAt":"2026-05-11T20:53:12.493Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7ac07a26dea79c3892436bce41cce03dcbd3c4c7","status":"affected","lessThan":"c7ee791e538537b281f60945298796f0a3971bbd","versionType":"git"},{"version":"7ac07a26dea79c3892436bce41cce03dcbd3c4c7","status":"affected","lessThan":"843d366ff19708668d95cda16bb8aba109a93dba","versionType":"git"},{"version":"7ac07a26dea79c3892436bce41cce03dcbd3c4c7","status":"affected","lessThan":"f364cdeb38938f9d03061682b8ff3779dd1730e5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/zram/zram_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.6.84","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.2","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/zram/zram_drv.c"]}],"references":["https://git.kernel.org/stable/c/c7ee791e538537b281f60945298796f0a3971bbd","https://git.kernel.org/stable/c/843d366ff19708668d95cda16bb8aba109a93dba","https://git.kernel.org/stable/c/f364cdeb38938f9d03061682b8ff3779dd1730e5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:08:04.920Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/53xxx/CVE-2024-53222.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-53222","state":"PUBLISHED","datePublished":"2024-12-27T13:50:12.652Z","dateUpdated":"2026-05-11T20:53:12.493Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-11-19T17:17:25.024Z"},"containers":{"cna":{"title":"zram: fix NULL pointer in comp_algorithm_show()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nzram: fix NULL pointer in comp_algorithm_show()\n\nLTP reported a NULL pointer dereference as followed:\n\n CPU: 7 UID: 0 PID: 5995 Comm: cat Kdump: loaded Not tainted 6.12.0-rc6+ #3\n Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015\n pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n pc : __pi_strcmp+0x24/0x140\n lr : zcomp_available_show+0x60/0x100 [zram]\n sp : ffff800088b93b90\n x29: ffff800088b93b90 x28: 0000000000000001 x27: 0000000000400cc0\n x26: 0000000000000ffe x25: ffff80007b3e2388 x24: 0000000000000000\n x23: ffff80007b3e2390 x22: ffff0004041a9000 x21: ffff80007b3e2900\n x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000\n x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000\n x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000\n x11: 0000000000000000 x10: ffff80007b3e2900 x9 : ffff80007b3cb280\n x8 : 0101010101010101 x7 : 0000000000000000 x6 : 0000000000000000\n x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00656c722d6f7a6c\n x2 : 0000000000000000 x1 : ffff80007b3e2900 x0 : 0000000000000000\n Call trace:\n  __pi_strcmp+0x24/0x140\n  comp_algorithm_show+0x40/0x70 [zram]\n  dev_attr_show+0x28/0x80\n  sysfs_kf_seq_show+0x90/0x140\n  kernfs_seq_show+0x34/0x48\n  seq_read_iter+0x1d4/0x4e8\n  kernfs_fop_read_iter+0x40/0x58\n  new_sync_read+0x9c/0x168\n  vfs_read+0x1a8/0x1f8\n  ksys_read+0x74/0x108\n  __arm64_sys_read+0x24/0x38\n  invoke_syscall+0x50/0x120\n  el0_svc_common.constprop.0+0xc8/0xf0\n  do_el0_svc+0x24/0x38\n  el0_svc+0x38/0x138\n  el0t_64_sync_handler+0xc0/0xc8\n  el0t_64_sync+0x188/0x190\n\nThe zram->comp_algs[ZRAM_PRIMARY_COMP] can be NULL in zram_add() if\ncomp_algorithm_set() has not been called.  User can access the zram device\nby sysfs after device_add_disk(), so there is a time window to trigger the\nNULL pointer dereference.  Move it ahead device_add_disk() to make sure\nwhen user can access the zram device, it is ready.  comp_algorithm_set()\nis protected by zram->init_lock in other places and no such problem."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7ac07a26dea79c3892436bce41cce03dcbd3c4c7","status":"affected","lessThan":"c7ee791e538537b281f60945298796f0a3971bbd","versionType":"git"},{"version":"7ac07a26dea79c3892436bce41cce03dcbd3c4c7","status":"affected","lessThan":"843d366ff19708668d95cda16bb8aba109a93dba","versionType":"git"},{"version":"7ac07a26dea79c3892436bce41cce03dcbd3c4c7","status":"affected","lessThan":"f364cdeb38938f9d03061682b8ff3779dd1730e5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/zram/zram_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.6.84","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.2","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/zram/zram_drv.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c7ee791e538537b281f60945298796f0a3971bbd"},{"url":"https://git.kernel.org/stable/c/843d366ff19708668d95cda16bb8aba109a93dba"},{"url":"https://git.kernel.org/stable/c/f364cdeb38938f9d03061682b8ff3779dd1730e5"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T20:53:12.493Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.84"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.12.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.13"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}