Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak
Fix a KMSAN kernel-infoleak detected by the syzbot .
[net?] KMSAN: kernel-infoleak in __skb_datagram_iter
In tcf_ife_dump(), the variable ‘opt’ was partially initialized using a designatied initializer. While the padding bytes are reamined uninitialized. nla_put() copies the entire structure into a netlink message, these uninitialized bytes leaked to userspace.
Initialize the structure with memset before assigning its fields to ensure all members and padding are cleared prior to beign copied.
This change silences the KMSAN report and prevents potential information leaks from the kernel memory.
This fix has been tested and validated by syzbot. This patch closes the bug reported at the following syzkaller link and ensures no infoleak.
Details
- Affected product:
- Oracle Linux 7 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+1 more)
In the Linux kernel, the following vulnerability has been resolved:
net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak
Fix a KMSAN kernel-infoleak detected by the syzbot .
[net?] KMSAN: kernel-infoleak in __skb_datagram_iter
In tcf_ife_dump(), the variable ‘opt’ was partially initialized using a designatied initializer. While the padding bytes are reamined uninitialized. nla_put() copies the entire structure into a netlink message, these uninitialized bytes leaked to userspace.
Initialize the structure with memset before assigning its fields to ensure all members and padding are cleared prior to beign copied.
This change silences the KMSAN report and prevents potential information leaks from the kernel memory.
This fix has been tested and validated by syzbot. This patch closes the bug reported at the following syzkaller link and ensures no infoleak.