The patch titled Subject: mm: mempolicy: require at least one nodeid for MPOL_PREFERRED has been added to the -mm tree. Its filename is mm-mempolicy-require-at-least-one-nodeid-for-mpol_preferred.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-mempolicy-require-at-least-one-nodeid-for-mpol_preferred.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-mempolicy-require-at-least-one-nodeid-for-mpol_preferred.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/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Subject: mm: mempolicy: require at least one nodeid for MPOL_PREFERRED Using an empty (malformed) nodelist that is not caught during mount option parsing leads to a stack-out-of-bounds access. The option string that was used was: "mpol=prefer:,". However, MPOL_PREFERRED requires a single node number, which is not being provided here. Add a check that 'nodes' is not empty after parsing for MPOL_PREFERRED's nodeid. Link: http://lkml.kernel.org/r/89526377-7eb6-b662-e1d8-4430928abde9@xxxxxxxxxxxxx Fixes: 095f1fc4ebf3 ("mempolicy: rework shmem mpol parsing and display") Reported-by: Entropy Moe <3ntr0py1337@xxxxxxxxx> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mempolicy.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/mm/mempolicy.c~mm-mempolicy-require-at-least-one-nodeid-for-mpol_preferred +++ a/mm/mempolicy.c @@ -2897,7 +2897,9 @@ int mpol_parse_str(char *str, struct mem switch (mode) { case MPOL_PREFERRED: /* - * Insist on a nodelist of one node only + * Insist on a nodelist of one node only, although later + * we use first_node(nodes) to grab a single node, so here + * nodelist (or nodes) cannot be empty. */ if (nodelist) { char *rest = nodelist; @@ -2905,6 +2907,8 @@ int mpol_parse_str(char *str, struct mem rest++; if (*rest) goto out; + if (nodes_empty(nodes)) + goto out; } break; case MPOL_INTERLEAVE: _ Patches currently in -mm which might be from rdunlap@xxxxxxxxxxxxx are mm-mempolicy-require-at-least-one-nodeid-for-mpol_preferred.patch mm-hugetlbc-fix-printk-format-warning-for-32-bit-phys_addr_t.patch bus-mhi-fix-printk-format-for-size_t.patch