Bug 2396382 (CVE-2023-53375)
| Summary: | CVE-2023-53375 kernel: Linux kernel: Memory leak in tracing error log management causes denial of service | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's tracing functionality. When a tracing instance is removed, the system fails to free the associated error logs, resulting in a memory leak. A local attacker can exploit this vulnerability by repeatedly creating and removing tracing instances, which may lead to memory exhaustion and a denial of service (DoS) on the system.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: tracing: Free error logs of tracing instances When a tracing instance is removed, the error messages that hold errors that occurred in the instance needs to be freed. The following reports a memory leak: # cd /sys/kernel/tracing # mkdir instances/foo # echo 'hist:keys=x' > instances/foo/events/sched/sched_switch/trigger # cat instances/foo/error_log [ 117.404795] hist:sched:sched_switch: error: Couldn't find field Command: hist:keys=x ^ # rmdir instances/foo Then check for memory leaks: # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff88810d8ec700 (size 192): comm "bash", pid 869, jiffies 4294950577 (age 215.752s) hex dump (first 32 bytes): 60 dd 68 61 81 88 ff ff 60 dd 68 61 81 88 ff ff `.ha....`.ha.... a0 30 8c 83 ff ff ff ff 26 00 0a 00 00 00 00 00 .0......&....... backtrace: [<00000000dae26536>] kmalloc_trace+0x2a/0xa0 [<00000000b2938940>] tracing_log_err+0x277/0x2e0 [<000000004a0e1b07>] parse_atom+0x966/0xb40 [<0000000023b24337>] parse_expr+0x5f3/0xdb0 [<00000000594ad074>] event_hist_trigger_parse+0x27f8/0x3560 [<00000000293a9645>] trigger_process_regex+0x135/0x1a0 [<000000005c22b4f2>] event_trigger_write+0x87/0xf0 [<000000002cadc509>] vfs_write+0x162/0x670 [<0000000059c3b9be>] ksys_write+0xca/0x170 [<00000000f1cddc00>] do_syscall_64+0x3e/0xc0 [<00000000868ac68c>] entry_SYSCALL_64_after_hwframe+0x72/0xdc unreferenced object 0xffff888170c35a00 (size 32): comm "bash", pid 869, jiffies 4294950577 (age 215.752s) hex dump (first 32 bytes): 0a 20 20 43 6f 6d 6d 61 6e 64 3a 20 68 69 73 74 . Command: hist 3a 6b 65 79 73 3d 78 0a 00 00 00 00 00 00 00 00 :keys=x......... backtrace: [<000000006a747de5>] __kmalloc+0x4d/0x160 [<000000000039df5f>] tracing_log_err+0x29b/0x2e0 [<000000004a0e1b07>] parse_atom+0x966/0xb40 [<0000000023b24337>] parse_expr+0x5f3/0xdb0 [<00000000594ad074>] event_hist_trigger_parse+0x27f8/0x3560 [<00000000293a9645>] trigger_process_regex+0x135/0x1a0 [<000000005c22b4f2>] event_trigger_write+0x87/0xf0 [<000000002cadc509>] vfs_write+0x162/0x670 [<0000000059c3b9be>] ksys_write+0xca/0x170 [<00000000f1cddc00>] do_syscall_64+0x3e/0xc0 [<00000000868ac68c>] entry_SYSCALL_64_after_hwframe+0x72/0xdc The problem is that the error log needs to be freed when the instance is removed.