In net/socket.c in the Linux kernel through 4.17.1, there is a race condition between fchownat and close in cases where they target the same socket file descriptor, related to the sock_close and sockfs_setattr functions. fchownat does not increment the file descriptor reference count, which allows close to set the socket to NULL during fchownat's execution, leading to a NULL pointer dereference and system crash.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
| Link | Tags |
|---|---|
| https://usn.ubuntu.com/3752-2/ | vendor advisory |
| https://usn.ubuntu.com/3752-3/ | vendor advisory |
| http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6d8c50dcb029872b298eea68cc6209c866fd3e14 | third party advisory patch |
| https://patchwork.ozlabs.org/patch/926519/ | third party advisory patch |
| https://access.redhat.com/errata/RHSA-2018:2948 | vendor advisory |
| https://lkml.org/lkml/2018/6/5/14 | third party advisory |
| http://www.securityfocus.com/bid/104453 | vdb entry third party advisory |
| https://usn.ubuntu.com/3752-1/ | vendor advisory |
| https://github.com/torvalds/linux/commit/6d8c50dcb029872b298eea68cc6209c866fd3e14 | third party advisory patch |