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.
- Upgrade
Upgrade
ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1112.119~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1117.126~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1117.126~20.04.2 - Upgrade
Upgrade
ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1112.122~20.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-186.196~20.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1106.110~20.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1107.113~20.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-184.194~20.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1064.66~20.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1109.115~20.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1106.110~20.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-186.196 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1112.119 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1117.126 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1117.126 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1112.122 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1108.114 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1095.103 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1106.110 - Upgrade
Upgrade
ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1107.113 - Upgrade
Upgrade
ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1104.109 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-184.194 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1107.108 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1064.66 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1053.53 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1109.115 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 5.15.0-1106.109 - Upgrade
Upgrade
ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.15.0-1075.79 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1096.98 - Upgrade
Upgrade
ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1104.106 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1111.120 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1112.119+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1117.126+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-186.196+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1112.122+fips1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.0.10-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 5.10.260 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 5.15.209 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.0.10 - Compensating control
In netdevsim, free nsim_dev->fa_cookie in nsim_drv_remove() by adding kfree(nsim_dev->fa_cookie).
Event History
Frequently Asked Questions
Who is exposed to this issue?
Systems using the Linux kernel netdevsim component are exposed when a trap FA cookie is written through nsim_dev_trap_fa_cookie_write() and the simulated device is later removed.
What does an attacker or user need to do to trigger the leak?
A local user with the privileges needed to write the netdevsim trap FA cookie interface can trigger an allocation of fa_cookie. Removing the netdevsim device afterward leaves that allocation unfreed in affected kernels.
What is the impact of successful exploitation?
The issue is a kernel memory leak of the allocated fa_cookie object. Repeated triggering can consume kernel memory and affect system availability.
What can be done if the fix cannot be applied immediately?
Avoid writing the netdevsim trap FA cookie interface, or avoid using and removing netdevsim devices after such writes. Restrict local access to the relevant netdevsim interfaces.
How can administrators identify the issue?
Kernel memory-leak detection may report an unreferenced allocation originating from nsim_dev_trap_fa_cookie_write(), with a backtrace through __kmalloc and full_proxy_write. The leak occurs when the netdevsim device removal path does not free nsim_dev->fa_cookie.