3.8.13.21 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Artem Fetishev <[email protected]> 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 <[email protected]> Signed-off-by: Aleksandr Terekhov <[email protected]> Reported-by: <[email protected]> Acked-by: Pavel Emelyanov <[email protected]> Acked-by: Cyrill Gorcunov <[email protected]> Reviewed-by: "Eric W. Biederman" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- fs/proc/base.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index 9b43ff77..78150a0 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1784,6 +1784,7 @@ 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) { -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
