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| author | Dominique Martinet <dominique.martinet@cea.fr> | 2018-08-14 02:43:48 +0000 |
|---|---|---|
| committer | Dominique Martinet <dominique.martinet@cea.fr> | 2018-08-27 14:59:29 +0900 |
| commit | 2f9ad0ac947ccbe3ffe7c6229c9330f2a7755f64 (patch) | |
| tree | 467a3db6b689c4cfcb49834890a6381ae168b0be /net/9p | |
| parent | 5b394b2ddf0347bef56e50c69a58773c94343ff3 (diff) | |
| download | lwn-2f9ad0ac947ccbe3ffe7c6229c9330f2a7755f64.tar.gz lwn-2f9ad0ac947ccbe3ffe7c6229c9330f2a7755f64.zip | |
9p/xen: fix check for xenbus_read error in front_probe
If the xen bus exists but does not expose the proper interface, it is
possible to get a non-zero length but still some error, leading to
strcmp failing trying to load invalid memory addresses e.g.
fffffffffffffffe.
There is then no need to check length when there is no error, as the
xenbus driver guarantees that the string is nul-terminated.
Link: http://lkml.kernel.org/r/1534236007-10170-1-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Diffstat (limited to 'net/9p')
| -rw-r--r-- | net/9p/trans_xen.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index c2d54ac76bfd..843cb823d9b9 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -391,8 +391,8 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev, unsigned int max_rings, max_ring_order, len = 0; versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); - if (!len) - return -EINVAL; + if (IS_ERR(versions)) + return PTR_ERR(versions); if (strcmp(versions, "1")) { kfree(versions); return -EINVAL; |