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authorMiklos Szeredi <mszeredi@redhat.com>2018-07-26 16:13:11 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2018-07-26 16:13:11 +0200
commite8f3bd773d22f488724dffb886a1618da85c2966 (patch)
tree5edce11e41e1a089911ccfc18c1a3d941c5b3b39 /fs/fuse
parentfuse: umount should wait for all requests (diff)
downloadlinux-e8f3bd773d22f488724dffb886a1618da85c2966.tar.xz
linux-e8f3bd773d22f488724dffb886a1618da85c2966.zip
fuse: Fix oops at process_init_reply()
syzbot is hitting NULL pointer dereference at process_init_reply(). This is because deactivate_locked_super() is called before response for initial request is processed. Fix this by aborting and waiting for all requests (including FUSE_INIT) before resetting fc->sb. Original patch by Tetsuo Handa <penguin-kernel@I-love.SKAURA.ne.jp>. Reported-by: syzbot <syzbot+b62f08f4d5857755e3bc@syzkaller.appspotmail.com> Fixes: e27c9d3877a0 ("fuse: fuse: add time_gran to INIT_OUT") Cc: <stable@vger.kernel.org> # v3.19 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/inode.c25
1 files changed, 11 insertions, 14 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index eeab70e7904d..0115c2f0a428 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -391,11 +391,6 @@ static void fuse_put_super(struct super_block *sb)
{
struct fuse_conn *fc = get_fuse_conn_super(sb);
- fuse_send_destroy(fc);
-
- fuse_abort_conn(fc, false);
- fuse_wait_aborted(fc);
-
mutex_lock(&fuse_mutex);
list_del(&fc->entry);
fuse_ctl_remove_conn(fc);
@@ -1212,16 +1207,25 @@ static struct dentry *fuse_mount(struct file_system_type *fs_type,
return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
}
-static void fuse_kill_sb_anon(struct super_block *sb)
+static void fuse_sb_destroy(struct super_block *sb)
{
struct fuse_conn *fc = get_fuse_conn_super(sb);
if (fc) {
+ fuse_send_destroy(fc);
+
+ fuse_abort_conn(fc, false);
+ fuse_wait_aborted(fc);
+
down_write(&fc->killsb);
fc->sb = NULL;
up_write(&fc->killsb);
}
+}
+static void fuse_kill_sb_anon(struct super_block *sb)
+{
+ fuse_sb_destroy(sb);
kill_anon_super(sb);
}
@@ -1244,14 +1248,7 @@ static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
static void fuse_kill_sb_blk(struct super_block *sb)
{
- struct fuse_conn *fc = get_fuse_conn_super(sb);
-
- if (fc) {
- down_write(&fc->killsb);
- fc->sb = NULL;
- up_write(&fc->killsb);
- }
-
+ fuse_sb_destroy(sb);
kill_block_super(sb);
}