Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix memory leak in cifs_construct_tcon()
When having a multiuser mount with domain= specified and using cifscreds, cifs_set_cifscreds() will end up setting @ctx->domainname, so it needs to be freed before leaving cifs_construct_tcon().
This fixes the following memory leak reported by kmemleak:
mount.cifs //srv/share /mnt -o domain=ZELDA,multiuser,… su - testuser cifscreds add -d ZELDA -u testuser … ls /mnt/1 … umount /mnt echo scan > /sys/kernel/debug/kmemleak cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8881203c3f08 (size 8): comm “ls”, pid 5060, jiffies 4307222943 hex dump (first 8 bytes): 5a 45 4c 44 41 00 cc cc ZELDA… backtrace (crc d109a8cf): __kmalloc_node_track_caller_noprof+0x572/0x710 kstrdup+0x3a/0x70 cifs_sb_tlink+0x1209/0x1770 [cifs] cifs_get_fattr+0xe1/0xf50 [cifs] cifs_get_inode_info+0xb5/0x240 [cifs] cifs_revalidate_dentry_attr+0x2d1/0x470 [cifs] cifs_getattr+0x28e/0x450 [cifs] vfs_getattr_nosec+0x126/0x180 vfs_statx+0xf6/0x220 do_statx+0xab/0x110 __x64_sys_statx+0xd5/0x130 do_syscall_64+0xbb/0x380 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Details
- Affected product:
- Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | Released |
32 kernels
|
| Debian 13 | Will Not Fix | — |
| Oracle Linux 8 UEK 7 | Planned | — |
| Oracle Linux 9 UEK 7 | Planned | — |
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
57 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
40 kernels
|
| Ubuntu 22.04 | Released |
90 kernels
|
| Ubuntu 22.04 AWS | Released |
81 kernels
|
| Ubuntu 22.04 Azure | Released |
73 kernels
|
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |