netfs: Fix uninitialized return value in netfs_unbuffered_write()
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 91% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix uninitialized return value in netfs_unbuffered_write()
If preparation of the first subrequest fails,
netfs_unbuffered_write() exits its loop before ret is initialized. The
empty-iterator check can do the same.
For synchronous writes, netfs_unbuffered_write_iter_locked() may then
return an unrelated error instead of wreq->error. This is reachable
through CIFS if cifs_prepare_write() fails to reopen the file or obtain
credits.
Initialize ret to 0 so the caller returns wreq->error if no data was
written, or the number of bytes already written otherwise.
Found with Clang's -Wconditional-uninitialized.
Affected products
Linux · Linux