The patch titled Subject: fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp has been added to the -mm tree. Its filename is fs-hfs-fix-comparison-bug-in-hfs_cat_keycmp.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fs-hfs-fix-comparison-bug-in-hfs_cat_keycmp.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/fs-hfs-fix-comparison-bug-in-hfs_cat_keycmp.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Subject: fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp Relying on the sign (after casting to int) of the difference of two quantities for comparison is usually wrong. For example, should a-b turn out to be 2^31, the return value of cmp(a,b) is -2^31; but that would also be the return value from cmp(b, a). So a compares less than b and b compares less than a. One can also easily find three values a,b,c such that a compares less than b, b compares less than c, but a does not compare less than c. Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Reviewed-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/hfs/catalog.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff -puN fs/hfs/catalog.c~fs-hfs-fix-comparison-bug-in-hfs_cat_keycmp fs/hfs/catalog.c --- a/fs/hfs/catalog.c~fs-hfs-fix-comparison-bug-in-hfs_cat_keycmp +++ a/fs/hfs/catalog.c @@ -162,14 +162,16 @@ err2: */ int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2) { - int retval; + __be32 k1p, k2p; - retval = be32_to_cpu(key1->cat.ParID) - be32_to_cpu(key2->cat.ParID); - if (!retval) - retval = hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len, - key2->cat.CName.name, key2->cat.CName.len); + k1p = key1->cat.ParID; + k2p = key2->cat.ParID; - return retval; + if (k1p != k2p) + return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1; + + return hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len, + key2->cat.CName.name, key2->cat.CName.len); } /* Try to get a catalog entry for given catalog id */ _ Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are origin.patch lib-lcmc-ensure-correct-result-whenever-it-fits.patch lib-lcmc-lcmn0=lcm0n-is-0-not-n.patch fs-hfs-fix-comparison-bug-in-hfs_cat_keycmp.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html