smb: client: validate absolute native symlink targets before NT fixups
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.16, 7.2.8
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: smb: client: validate absolute native symlink targets before NT fixups With symlinkroot unset, an absolute target is copied without conversion to an NT drive path. Later code still assumes an NT prefix is present when modifying the target and calculating the print name length. For "/ab", this causes two failures: sym[5] and path[5] are written past their allocations, and plen -= 2 * poff subtracts an assumed 8-byte prefix from a 6-byte UTF-16 target, wrapping u16 plen to 65534. That underflow causes another overflow: memcpy() copies 65534 bytes into a 24-byte buffer. A user with write access to a mounted share can trigger these bugs with default settings. Validate the NT drive prefix, including an ASCII drive letter, before accessing fixed offsets or subtracting the prefix length.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 3363da82e02f1bddc54faa92ea430c6532e2cd2e · fixed in 6913ff607c2bc8694193e1fcc40bf16d75f35f16; From 3363da82e02f1bddc54faa92ea430c6532e2cd2e · fixed in 23c240d9509e15f72e4112fc95f0160ab32ec430; From 6.15.6 · fixed in 6.16
- Linux Linux
6.16
- KernelLinux
From 6.16.0 · fixed in 7.2.8