Commit 7d95178c authored Aug 01, 2018 by Theodore Ts'o

ext4: check for NUL characters in extended attribute's name

Extended attribute names are defined to be NUL-terminated, so the name
must not contain a NUL character.  This is important because there are
places when remove extended attribute, the code uses strlen to
determine the length of the entry.  That should probably be fixed at
some point, but code is currently really messy, so the simplest fix
for now is to simply validate that the extended attributes are sane.

https://bugzilla.kernel.org/show_bug.cgi?id=200401



Reported-by: Wen Xu <wen.xu@gatech.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

parent 5ef2a699

fs/ext4/xattr.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -190,6 +190,8 @@ ext4_xattr_check_entries(struct ext4_xattr_entry entry, void end,
		struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
		if ((void *)next >= end)
		return -EFSCORRUPTED;
		if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
		return -EFSCORRUPTED;
		e = next;
		}

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