title: hwrng: core - Fix page fault dead lock on mmap-ed hwrng
description: In the Linux kernel, the following vulnerability has been resolved:
hwrng: core - Fix page fault dead lock on mmap-ed hwrng
There is a dead-lock in the hwrng device read path.  This triggers
when the user reads from /dev/hwrng into memory also mmap-ed from
/dev/hwrng.  The resulting page fault triggers a recursive read
which then dead-locks.
Fix this by using a stack buffer when calling copy_to_user.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 9996508b3353, lessThan: eafd83b92f6c, status: affected, versionType: git
version: 9996508b3353, lessThan: 5030d4c79886, status: affected, versionType: git
version: 9996508b3353, lessThan: c6a8111aacbf, status: affected, versionType: git
version: 9996508b3353, lessThan: 26cc6d7006f9, status: affected, versionType: git
version: 9996508b3353, lessThan: aa8aa16ed9ad, status: affected, versionType: git
version: 9996508b3353, lessThan: ecabe8cd456d, status: affected, versionType: git
version: 9996508b3353, lessThan: 6822a1427178, status: affected, versionType: git
version: 9996508b3353, lessThan: 78aafb3884f6, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 2.6.33, status: affected
version: 0, lessThan: 2.6.33, status: unaffected, versionType: custom
version: 4.19.307, lessThanOrEqual: 4.19.*, status: unaffected, versionType: custom
version: 5.4.269, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.210, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.15.149, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.76, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.6.15, lessThanOrEqual: 6.6.*, status: unaffected, versionType: custom
version: 6.7.3, lessThanOrEqual: 6.7.*, status: unaffected, versionType: custom
version: 6.8, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
