[PATCH] fix page leak during core dump

When the dump cannot occur most likely because of a full file system and
the page to be written is the zero page, the call to page_cache_release()
is missed.

Signed-off-by: Brian Pomerantz <bapper@mvista.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 5 insertions, 2 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index a2fceba7ef8e..9cc4f0a8aaae 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1704,7 +1704,10 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
                                 DUMP_SEEK(PAGE_SIZE);
                         } else {
                                 if (page == ZERO_PAGE(addr)) {
-                                        DUMP_SEEK(PAGE_SIZE);
+                                        if (!dump_seek(file, PAGE_SIZE)) {
+                                                page_cache_release(page);
+                                                goto end_coredump;
+                                        }
                                 } else {
                                         void *kaddr;
                                         flush_cache_page(vma, addr,
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 47d6d49d1fb9..f3ddca4a387b 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1480,8 +1480,8 @@ static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
                         }
                         else if (page == ZERO_PAGE(addr)) {
-                                DUMP_SEEK(file->f_pos + PAGE_SIZE);
                                 page_cache_release(page);
+                                DUMP_SEEK(file->f_pos + PAGE_SIZE);
                         }
                         else {
                                 void *kaddr;