Messages in this thread | | | Date | Wed, 21 Sep 2022 12:38:15 +0800 | Subject | Re: [REPOST PATCH v3 0/2] vfs: fix a mount table handling problem | From | Ian Kent <> |
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On 21/9/22 09:20, Theodore Ts'o wrote: > On Tue, Sep 20, 2022 at 03:26:17PM +0800, Ian Kent wrote: >> Whenever a mount has an empty "source" (aka mnt_fsname), the glibc >> function getmntent incorrectly parses its input, resulting in reporting >> incorrect data to the caller. >> >> The problem is that the get_mnt_entry() function in glibc's >> misc/mntent_r.c assumes that leading whitespace on a line can always >> be discarded because it will always be followed by a # for the case >> of a comment or a non-whitespace character that's part of the value >> of the first field. However, this assumption is violated when the >> value of the first field is an empty string. >> >> This is fixed in the mount API code by simply checking for a pointer >> that contains a NULL and treating it as a NULL pointer. > Why not simply have the mount API code disallow a zero-length "source" > / mnt_fsname?
Hi Ted,
I suppose but it seems to me that, for certain file systems, mostly
pseudo file systems, the source isn't needed and is left out ... so
disallowing a zero length source could lead to quite a bit of breakage.
Ian
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