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authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>2009-10-26 16:49:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-10-29 07:39:29 -0700
commitab8a3e14e6f8e567560f664bbd29aefb306a274e (patch)
tree72de6b1c5a9130a0503ecc4d9e16db236f6884a0 /mm/mempolicy.c
parent47f365eb575735c6b2edf5d08e0d16d26a9c23bd (diff)
downloadvexpress-lsk-ab8a3e14e6f8e567560f664bbd29aefb306a274e.tar.gz
mbind(): fix leak of never putback pages
If mbind() receives an invalid address, do_mbind leaks a page. The following test program detects this leak. This patch fixes it. migrate_efault.c ======================================= #include <numaif.h> #include <numa.h> #include <sys/mman.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <string.h> static unsigned long pagesize; static void* make_hole_mapping(void) { void* addr; addr = mmap(NULL, pagesize*3, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, 0, 0); if (addr == MAP_FAILED) return NULL; /* make page populate */ memset(addr, 0, pagesize*3); /* make memory hole */ munmap(addr+pagesize, pagesize); return addr; } int main(int argc, char** argv) { void* addr; int ch; int node; struct bitmask *nmask = numa_allocate_nodemask(); int err; int node_set = 0; while ((ch = getopt(argc, argv, "n:")) != -1){ switch (ch){ case 'n': node = strtol(optarg, NULL, 0); numa_bitmask_setbit(nmask, node); node_set = 1; break; default: ; } } argc -= optind; argv += optind; if (!node_set) numa_bitmask_setbit(nmask, 0); pagesize = getpagesize(); addr = make_hole_mapping(); err = mbind(addr, pagesize*3, MPOL_BIND, nmask->maskp, nmask->size, MPOL_MF_MOVE_ALL); if (err) perror("mbind "); return 0; } ======================================= Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempolicy.c')
-rw-r--r--mm/mempolicy.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 7dd9d9f8069..d49956d3025 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1058,7 +1058,8 @@ static long do_mbind(unsigned long start, unsigned long len,
if (!err && nr_failed && (flags & MPOL_MF_STRICT))
err = -EIO;
- }
+ } else
+ putback_lru_pages(&pagelist);
up_write(&mm->mmap_sem);
mpol_put(new);