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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-22 17:11:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-22 17:11:38 -0700
commitf320ac6e131669345c7f4abefbb228b570eb9199 (patch)
treeec1e3f0d43b3ebfdcacfd8f47a649ce36f9dba6a
parentc3d8f220d01220a5b253e422be407d068dc65511 (diff)
parent52c479697c9b73f628140dcdfcd39ea302d05482 (diff)
Merge branch 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull epoll fixes from Al Viro: "Fix reference counting and clean up exit paths" * 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: do_epoll_ctl(): clean the failure exits up a bit epoll: Keep a reference on files added to the check list
-rw-r--r--fs/eventpoll.c26
1 files changed, 13 insertions, 13 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 12eebcdea9c8..e0decff22ae2 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1994,9 +1994,11 @@ static int ep_loop_check_proc(void *priv, void *cookie, int call_nests)
* not already there, and calling reverse_path_check()
* during ep_insert().
*/
- if (list_empty(&epi->ffd.file->f_tfile_llink))
+ if (list_empty(&epi->ffd.file->f_tfile_llink)) {
+ get_file(epi->ffd.file);
list_add(&epi->ffd.file->f_tfile_llink,
&tfile_check_list);
+ }
}
}
mutex_unlock(&ep->mtx);
@@ -2040,6 +2042,7 @@ static void clear_tfile_check_list(void)
file = list_first_entry(&tfile_check_list, struct file,
f_tfile_llink);
list_del_init(&file->f_tfile_llink);
+ fput(file);
}
INIT_LIST_HEAD(&tfile_check_list);
}
@@ -2200,25 +2203,22 @@ int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
full_check = 1;
if (is_file_epoll(tf.file)) {
error = -ELOOP;
- if (ep_loop_check(ep, tf.file) != 0) {
- clear_tfile_check_list();
+ if (ep_loop_check(ep, tf.file) != 0)
goto error_tgt_fput;
- }
- } else
+ } else {
+ get_file(tf.file);
list_add(&tf.file->f_tfile_llink,
&tfile_check_list);
+ }
error = epoll_mutex_lock(&ep->mtx, 0, nonblock);
- if (error) {
-out_del:
- list_del(&tf.file->f_tfile_llink);
+ if (error)
goto error_tgt_fput;
- }
if (is_file_epoll(tf.file)) {
tep = tf.file->private_data;
error = epoll_mutex_lock(&tep->mtx, 1, nonblock);
if (error) {
mutex_unlock(&ep->mtx);
- goto out_del;
+ goto error_tgt_fput;
}
}
}
@@ -2239,8 +2239,6 @@ out_del:
error = ep_insert(ep, epds, tf.file, fd, full_check);
} else
error = -EEXIST;
- if (full_check)
- clear_tfile_check_list();
break;
case EPOLL_CTL_DEL:
if (epi)
@@ -2263,8 +2261,10 @@ out_del:
mutex_unlock(&ep->mtx);
error_tgt_fput:
- if (full_check)
+ if (full_check) {
+ clear_tfile_check_list();
mutex_unlock(&epmutex);
+ }
fdput(tf);
error_fput: