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| author | Miklos Szeredi <mszeredi@redhat.com> | 2018-07-26 17:13:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-05 10:18:39 +0300 |
| commit | c93ce9b00b9aa4bae06b758223ff62ca799522c6 (patch) | |
| tree | cfd7bbe84bf541f24509f060aaa43d545be44ceb | |
| parent | 4d6ef17a060cb227007a7dec6aa886abc4c01297 (diff) | |
| download | linux-c93ce9b00b9aa4bae06b758223ff62ca799522c6.tar.xz | |
fuse: Fix oops at process_init_reply()
commit e8f3bd773d22f488724dffb886a1618da85c2966 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fuse/inode.c | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9517154ddd29..4b2eb65be0d4 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -379,11 +379,6 @@ 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); - fuse_wait_aborted(fc); - mutex_lock(&fuse_mutex); list_del(&fc->entry); fuse_ctl_remove_conn(fc); @@ -1174,16 +1169,25 @@ 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); + 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); } @@ -1206,14 +1210,7 @@ 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); } |