CVE-2022-48635 fsdax: Fix infinite loop in dax_iomap_rw()
A local attacker can cause an infinite loop and system hang by triggering a specific read operation in the Linux kernel's DAX filesystem implementation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-48635?
CVE-2022-48635 is a medium-severity denial of service vulnerability in Linux kernel, published on 28 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
fsdax: Fix infinite loop in dax_iomap_rw()
I got an infinite loop and a WARNING report when executing a tail command in virtiofs.
WARNING: CPU: 10 PID: 964 at fs/iomap/iter.c:34 iomap_iter+0x3a2/0x3d0 Modules linked in: CPU: 10 PID: 964 Comm: tail Not tainted 5.19.0-rc7 Call Trace: <TASK> dax_iomap_rw+0xea/0x620 ? __this_cpu_preempt_check+0x13/0x20 fuse_dax_read_iter+0x47/0x80 fuse_file_read_iter+0xae/0xd0 new_sync_read+0xfe/0x180 ? 0xffffffff81000000 vfs_read+0x14d/0x1a0 ksys_read+0x6d/0xf0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd
The tail command will call read() with a count of 0. In this case, iomap_iter() will report this WARNING, and always return 1 which casuing the infinite loop in dax_iomap_rw().
Fixing by checking count whether is 0 in dax_iomap_rw().
Weakness: CWE-835
Which versions are affected by CVE-2022-48635?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-48635?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-48635 being exploited?
There is no known exploitation of CVE-2022-48635 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-53846, AZL-53935, DEBIAN-CVE-2022-48635, GHSA-cghm-v6v8-jp7r, UBUNTU-CVE-2022-48635.