Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()
Syzbot reported that when searching for records in a directory where the inode’s i_size is corrupted and has a large value, memory access outside the folio/page range may occur, or a use-after-free bug may be detected if KASAN is enabled.
This is because nilfs_last_byte(), which is called by nilfs_find_entry() and others to calculate the number of valid bytes of directory data in a page from i_size and the page index, loses the upper 32 bits of the 64-bit size information due to an inappropriate type of local variable to which the i_size value is assigned.
This caused a large byte offset value due to underflow in the end address calculation in the calling nilfs_find_entry(), resulting in memory access that exceeds the folio/page size.
Fix this issue by changing the type of the local variable causing the bit loss from “unsigned int” to “u64”. The return value of nilfs_last_byte() is also of type “unsigned int”, but it is truncated so as not to exceed PAGE_SIZE and no bit loss occurs, so no change is required.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 6 ELS , CloudLinux 7 ELS , Debian 10 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 3.10.0 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2 5.10 | Will Not Fix | — |
| Amazon Linux 2 5.4 | Will Not Fix | — |
| Debian 11 | Planned | — |
| Debian 11 cloud | Planned | — |
| Debian 12 | Planned | — |
| Oracle Linux 7 UEK 6 | Ready For Release | — |
| Oracle Linux 8 UEK 6 | Ready For Release | — |
| Oracle Linux 8 UEK 7 | Released |
53 kernels
|
| Oracle Linux 9 UEK 7 | Released |
53 kernels
|
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 18.04 AWS Focal | Released |
56 kernels
|
| Ubuntu 18.04 HWE Focal | Released |
69 kernels
|
| Ubuntu 20.04 | Released |
122 kernels
|
| Ubuntu 20.04 AWS | Released |
105 kernels
|
| Ubuntu 20.04 Azure | Released |
95 kernels
|
| Ubuntu 20.04 GCP | Released |
28 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
52 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
36 kernels
|
| Ubuntu 22.04 | Released |
69 kernels
|
| Ubuntu 22.04 AWS | Released |
60 kernels
|
| Ubuntu 22.04 Azure | Released |
56 kernels
|
| Ubuntu 24.04 | Released |
20 kernels
|
| Ubuntu 24.04 AWS | Ready For Release | — |