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| author | Artem Fetishev <artem_fetishev@epam.com> | 2014-03-10 15:49:45 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-23 21:37:06 -0700 |
| commit | bfe635e52ede4c72819099b0fce72e28eec6e6c6 (patch) | |
| tree | b842fdd41d924e7b37de51da999fa8d68ce21cd8 | |
| parent | e877d416818ff7439d01f88bf6d70131a27f730e (diff) | |
| download | lwn-bfe635e52ede4c72819099b0fce72e28eec6e6c6.tar.gz lwn-bfe635e52ede4c72819099b0fce72e28eec6e6c6.zip | |
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/proc/base.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 9fc77b412ac4..754ac4ddd826 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2092,6 +2092,7 @@ 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) { |