Date: Sun, 31 Jan 2021 16:25:43 +0100 From: Andrea Venturoli <ml@netfence.it> To: freebsd-security@freebsd.org Subject: Re: [FreeBSD-Announce] FreeBSD Security Advisory FreeBSD-SA-21:01.fsdisclosure Message-ID: <15879d07-6563-f762-c93c-cf91c9516ce7@netfence.it> In-Reply-To: <f32df288-0d05-0ece-52e5-042fe93d6940@quip.cz> References: <20210129022826.C82C91DB44@freefall.freebsd.org> <f32df288-0d05-0ece-52e5-042fe93d6940@quip.cz>
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On 1/31/21 12:29 PM, Miroslav Lachman wrote: >> Several file systems were not properly initializing the d_off field of >> the dirent structures returned by VOP_READDIR. In particular, tmpfs(5), >> smbfs(5), autofs(5) and mqueuefs(5) were failing to do so. As a result, >> eight uninitialized kernel stack bytes may be leaked to userspace by >> these file systems. This problem is not present in FreeBSD 11. > > There is a Corrected in: stable/11, 11.4-STABLE and releng/11.4, > 11.4-RELEASE-p7, but later is a statement "This problem is not present > in FreeBSD 11". > What is true? Is it fixed in newer patchlevel of FreeBSD 11.4 or it was > not present in 11.x at all? My understanding is that the problem described in that paragraph does not affect 11.x, but the next one does (and is "Corrected..."). I.e. 11.x is affected by: > Additionally, msdosfs(5) was failing to zero-fill a pair of padding > fields in the dirent structure, resulting in a leak of three > uninitialized bytes. Is that right? bye av.
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