| From | Luis Henriques <> | Subject | [PATCH 3.11 087/144] fs/proc/base.c: fix GPF in /proc/$PID/map_files | Date | Tue, 1 Apr 2014 12:14:51 +0100 |
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3.11.10.7 -stable review patch. If anyone has any objections, please let me know.
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From: Artem Fetishev <artem_fetishev@epam.com>
commit 70335abb2689c8cd5df91bf2d95a65649addf50b upstream.
The expected logic of proc_map_files_get_link() is either to return 0 and initialize 'path' or return an error and leave 'path' uninitialized.
By the time dname_to_vma_addr() returns 0 the corresponding vma may have already be gone. In this case the path is not initialized but the return value is still 0. This results in 'general protection fault' inside d_path().
Steps to reproduce:
CONFIG_CHECKPOINT_RESTORE=y
fd = open(...); while (1) { mmap(fd, ...); munmap(fd, ...); }
ls -la /proc/$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: Luis Henriques <luis.henriques@canonical.com> --- fs/proc/base.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/proc/base.c b/fs/proc/base.c index 1485e38..c35eaa4 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) { -- 1.9.1
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