CVE-2022-49803: netdevsim: Fix memory leak of nsim_dev->fa_cookie
In the Linux kernel, the following vulnerability has been resolved:
netdevsim: Fix memory leak of nsimdev->facookie
kmemleak reports this issue:
unreferenced object 0xffff8881bac872d0 (size 8): comm "sh", pid 58603, jiffies 4481524462 (age 68.065s) hex dump (first 8 bytes): 04 00 00 00 de ad be ef ........ backtrace: [<00000000c80b8577>] kmalloc+0x49/0x150 [<000000005292b8c6>] nsimdevtrapfacookiewrite+0xc1/0x210 [netdevsim] [<0000000093d78e77>] fullproxywrite+0xf3/0x180 [<000000005a662c16>] vfswrite+0x1c5/0xaf0 [<000000007aabf84a>] ksyswrite+0xed/0x1c0 [<000000005f1d2e47>] dosyscall64+0x3b/0x90 [<000000006001c6ec>] entrySYSCALL64afterhwframe+0x63/0xcd
The issue occurs in the following scenarios:
nsimdevtrapfacookiewrite() kmalloc() facookie nsimdev->facookie = facookie .. nsimdrvremove()
The facookie allocked in nsimdevtrapfacookiewrite() is not freed. To fix, add kfree(nsimdev->facookie) to nsimdrvremove().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Operational
Apply the kernel fix: add `kfree(nsim_dev->fa_cookie)` to `nsim_drv_remove()` to free the `fa_cookie` allocated in `nsim_dev_trap_fa_cookie_write()` (reported by kmemleak as `netdevsim: Fix memory leak of nsim_dev->fa_cookie`).