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authorArtem Fetishev <artem_fetishev@epam.com>2014-03-10 15:49:45 -0700
committerJiri Slaby <jslaby@suse.cz>2014-03-22 22:01:59 +0100
commitccd13098cecd44d9b0694270100a700c46d52c28 (patch)
treed12673ddf60cefffd091415b74ee72cc168265c7 /fs/proc/base.c
parented279ab0b9662a197ddd26ba248272a693f0329f (diff)
fs/proc/base.c: fix GPF in /proc/$PID/map_files
commit 70335abb2689c8cd5df91bf2d95a65649addf50b upstream. The expected logic of proc_map_files_get_link() is either to return 0 and initialize 'path' or return an error and leave 'path' uninitialized. By the time dname_to_vma_addr() returns 0 the corresponding vma may have already be gone. In this case the path is not initialized but the return value is still 0. This results in 'general protection fault' inside d_path(). Steps to reproduce: CONFIG_CHECKPOINT_RESTORE=y fd = open(...); while (1) { mmap(fd, ...); munmap(fd, ...); } ls -la /proc/$PID/map_files Addresses https://bugzilla.kernel.org/show_bug.cgi?id=68991 Signed-off-by: Artem Fetishev <artem_fetishev@epam.com> Signed-off-by: Aleksandr Terekhov <aleksandr_terekhov@epam.com> Reported-by: <wiebittewas@gmail.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'fs/proc/base.c')
-rw-r--r--fs/proc/base.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1485e38daaa..c35eaa40493 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1813,6 +1813,7 @@ static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
if (rc)
goto out_mmput;
+ rc = -ENOENT;
down_read(&mm->mmap_sem);
vma = find_exact_vma(mm, vm_start, vm_end);
if (vma && vma->vm_file) {