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| author | Miklos Szeredi <mszeredi@redhat.com> | 2020-02-13 11:16:07 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-02-13 11:16:07 +0300 |
| commit | 3e8cb8b2eaeb22f540f1cbc00cbb594047b7ba89 (patch) | |
| tree | 216e3c9a7b853b2840a7de88faeb8dd65468de0f /fs/fuse/fuse_i.h | |
| parent | bb6d3fb354c5ee8d6bde2d576eb7220ea09862b9 (diff) | |
| download | linux-3e8cb8b2eaeb22f540f1cbc00cbb594047b7ba89.tar.xz | |
fuse: fix stack use after return
Normal, synchronous requests will have their args allocated on the stack.
After the FR_FINISHED bit is set by receiving the reply from the userspace
fuse server, the originating task may return and reuse the stack frame,
resulting in an Oops if the args structure is dereferenced.
Fix by setting a flag in the request itself upon initializing, indicating
whether it has an asynchronous ->end() callback.
Reported-by: Kyle Sanderson <kyle.leet@gmail.com>
Reported-by: Michael Stapelberg <michael+lkml@stapelberg.ch>
Fixes: 2b319d1f6f92 ("fuse: don't dereference req->args on finished request")
Cc: <stable@vger.kernel.org> # v5.4
Tested-by: Michael Stapelberg <michael+lkml@stapelberg.ch>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse/fuse_i.h')
| -rw-r--r-- | fs/fuse/fuse_i.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index aa75e2305b75..ca344bf71404 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -301,6 +301,7 @@ struct fuse_io_priv { * FR_SENT: request is in userspace, waiting for an answer * FR_FINISHED: request is finished * FR_PRIVATE: request is on private list + * FR_ASYNC: request is asynchronous */ enum fuse_req_flag { FR_ISREPLY, @@ -314,6 +315,7 @@ enum fuse_req_flag { FR_SENT, FR_FINISHED, FR_PRIVATE, + FR_ASYNC, }; /** |