Missing Release of Memory after Effective Lifetime
CVE-2021-46956
Summary
In the Linux kernel, the following vulnerability has been resolved: virtiofs: fix memory leak in virtio_fs_probe() When accidentally passing twice the same tag to qemu, kmemleak ended up reporting a memory leak in virtiofs. Also, looking at the log I saw the following error (that's when I realised the duplicated tag): virtiofs: probe of virtio5 failed with error -17 Here's the kmemleak log for reference: unreferenced object 0xffff888103d47800 (size 1024): comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................ backtrace: [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs] [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210 [<000000004d6baf3c>] really_probe+0xea/0x430 [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0 [<00000000196f47a7>] __driver_attach+0x98/0x140 [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0 [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0 [<0000000032b09ba7>] driver_register+0x8f/0xe0 [<00000000cdd55998>] 0xffffffffa002c013 [<000000000ea196a2>] do_one_initcall+0x64/0x2e0 [<0000000008f727ce>] do_init_module+0x5c/0x260 [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120 [<00000000ad2f48c6>] do_syscall_64+0x33/0x40 [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
- LOW
- LOCAL
- NONE
- UNCHANGED
- NONE
- LOW
- NONE
- HIGH
CWE-401 - Missing release of memory after effective lifetime (memory leak)
'Missing release of memory after effective lifetime (memory leak)' is a weakness that occurs when software doesn't effectively release allocated memory after it is used. If not addressed, this enables attackers to launch denial of service attacks (by crashing or hanging the program) or take advantage of other unexpected behavior resulting from low memory conditions.
References
Advisory Timeline
- Published