Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix possible UAF when remounting r/o a mmp-protected file system
After commit 618f003199c6 (“ext4: fix memory leak in ext4_fill_super”), after the file system is remounted read-only, there is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to point at freed memory, which the call to ext4_stop_mmpd() can trip over.
Fix this by only allowing kmmpd() to exit when it is stopped via ext4_stop_mmpd().
Bug-Report-Link: [email protected]
Details
- Affected product:
- CentOS 6 ELS , CentOS 7 ELS , CloudLinux 6 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel @ 3.10.0 (+8 more)
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix possible UAF when remounting r/o a mmp-protected file system
After commit 618f003199c6 (“ext4: fix memory leak in ext4_fill_super”), after the file system is remounted read-only, there is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to point at freed memory, which the call to ext4_stop_mmpd() can trip over.
Fix this by only allowing kmmpd() to exit when it is stopped via ext4_stop_mmpd().
Bug-Report-Link: [email protected]