Vulnerability CVE-2021-46956

Vulnerability CVE-2021-46956

Published: 2024-02-27

Description:

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

References:

https://git.kernel.org/stable/c/310efc95c72c13faf855c692d19cd4d054d827c8

https://git.kernel.org/stable/c/d19555ff225d0896a33246a49279e6d578095f15

https://git.kernel.org/stable/c/9b9d60c0eb8ada99cce2a9ab5c15dffc523b01ae

https://git.kernel.org/stable/c/5116e79fc6e6725b8acdad8b7e928a83ab7b47e6

https://git.kernel.org/stable/c/c79c5e0178922a9e092ec8fed026750f39dcaef4

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