Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix OOBs when building SMB2_IOCTL request
When using encryption, either enforced by the server or when using ‘seal’ mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command().
SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below:
mount.cifs //srv/share /mnt -o …,seal ln -s $(perl -e “print(‘a’)for 1..1024”) /mnt/link
BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859
CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.3-2.fc40 04/01/2014
Call Trace:
Details
- Affected product:
- AlmaLinux 9.2 ESU , Oracle Linux 7 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel-uek @ 5.4.17 (+3 more)
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix OOBs when building SMB2_IOCTL request
When using encryption, either enforced by the server or when using ‘seal’ mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command().
SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below:
mount.cifs //srv/share /mnt -o …,seal ln -s $(perl -e “print(‘a’)for 1..1024”) /mnt/link
BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859
CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.3-2.fc40 04/01/2014
Call Trace: