Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: tracing/histograms: Fix memory leak problem This reverts commit 46bbe5c671e06f070428b9be142cc4ee5cedebac. As commit 46bbe5c671e0 ("tracing: fix double free") said, the "double free" problem reported by clang static analyzer is: > In parse_var_defs() if there is a problem allocating > var_defs.expr, the earlier var_defs.name is freed. > This free is duplicated by free_var_defs() which frees > the rest of the list. However, if there is a problem allocating N-th var_defs.expr: + in parse_var_defs(), the freed 'earlier var_defs.name' is actually the N-th var_defs.name; + then in free_var_defs(), the names from 0th to (N-1)-th are freed; IF ALLOCATING PROBLEM HAPPENED HERE!!! -+ \ | 0th 1th (N-1)-th N-th V +-------------+-------------+-----+-------------+----------- var_defs: | name | expr | name | expr | ... | name | expr | name | /// +-------------+-------------+-----+-------------+----------- These two frees don't act on same name, so there was no "double free" problem before. Conversely, after that commit, we get a "memory leak" problem because the above "N-th var_defs.name" is not freed. If enable CONFIG_DEBUG_KMEMLEAK and inject a fault at where the N-th var_defs.expr allocated, then execute on shell like: $ echo 'hist:key=call_site:val=$v1,$v2:v1=bytes_req,v2=bytes_alloc' > \ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger Then kmemleak reports: unreferenced object 0xffff8fb100ef3518 (size 8): comm "bash", pid 196, jiffies 4295681690 (age 28.538s) hex dump (first 8 bytes): 76 31 00 00 b1 8f ff ff v1...... backtrace: [<0000000038fe4895>] kstrdup+0x2d/0x60 [<00000000c99c049a>] event_hist_trigger_parse+0x206f/0x20e0 [<00000000ae70d2cc>] trigger_process_regex+0xc0/0x110 [<0000000066737a4c>] event_trigger_write+0x75/0xd0 [<000000007341e40c>] vfs_write+0xbb/0x2a0 [<0000000087fde4c2>] ksys_write+0x59/0xd0 [<00000000581e9cdf>] do_syscall_64+0x3a/0x80 [<00000000cf3b065c>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 240dd5118a9e0454f280ffeae63f22bd14735733 before eb622d5580b9e2ff694f62da6410618bd73853cb; affected e92c490f104993cea35e5f5d5108ac12df1850ac before ecc6dec12c33aa92c086cd702af9f544ddaf3c75; affected 46bbe5c671e06f070428b9be142cc4ee5cedebac before 78a1400c42ee11197eb1f0f85ba51df9a4fdfff0; affected 46bbe5c671e06f070428b9be142cc4ee5cedebac before 22eeff55679d9e7c0f768c79bfbd83e2f8142d89; affected 46bbe5c671e06f070428b9be142cc4ee5cedebac before 4d453eb5e1eec89971aa5b3262857ee26cfdffd3; affected 46bbe5c671e06f070428b9be142cc4ee5cedebac before 7edc3945bdce9c39198a10d6129377a5c53559c2; affected e3a23511638a3dcf0275c1e71a46d1ca2e2e6788; affected 4.19.149 before 4.19.253; affected 5.4.69 before 5.4.207; affected 5.8.13 before 5.9 |
| Linux / Linux | affected 5.9; unaffected 0 before 5.9; unaffected 4.19.253 through 4.19.*; unaffected 5.4.207 through 5.4.*; unaffected 5.10.132 through 5.10.*; unaffected 5.15.56 through 5.15.*; unaffected 5.18.13 through 5.18.*; unaffected 5.19 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/eb622d5580b9e2ff694f62da6410618bd73853cb
- https://git.kernel.org/stable/c/ecc6dec12c33aa92c086cd702af9f544ddaf3c75
- https://git.kernel.org/stable/c/78a1400c42ee11197eb1f0f85ba51df9a4fdfff0
- https://git.kernel.org/stable/c/22eeff55679d9e7c0f768c79bfbd83e2f8142d89
- https://git.kernel.org/stable/c/4d453eb5e1eec89971aa5b3262857ee26cfdffd3
- https://git.kernel.org/stable/c/7edc3945bdce9c39198a10d6129377a5c53559c2
ADP enrichment
No English description supplied.
No references supplied.