diff options
| author | Kevin Brodsky <kevin.brodsky@arm.com> | 2025-11-26 12:48:35 +0000 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-11-26 10:59:18 -0700 |
| commit | c6a45ee7607de3a350008630f4369b1b5ac80884 (patch) | |
| tree | ef5b1e3f42c2044608c8529b2eda4f2d4c0ab6b0 | |
| parent | a857d99201cc4eb3cb78b9dcb6f1d027ef3ae699 (diff) | |
ublk: prevent invalid access with DEBUG
ublk_ch_uring_cmd_local() may jump to the out label before
initialising the io pointer. This will cause trouble if DEBUG is
defined, because the pr_devel() call dereferences io. Clang reports:
drivers/block/ublk_drv.c:2403:6: error: variable 'io' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
2403 | if (tag >= ub->dev_info.queue_depth)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/block/ublk_drv.c:2492:32: note: uninitialized use occurs here
2492 | __func__, cmd_op, tag, ret, io->flags);
|
Fix this by initialising io to NULL and checking it before
dereferencing it.
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/ublk_drv.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 75f210523e52..09718a68137c 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -2301,7 +2301,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, u16 buf_idx = UBLK_INVALID_BUF_IDX; struct ublk_device *ub = cmd->file->private_data; struct ublk_queue *ubq; - struct ublk_io *io; + struct ublk_io *io = NULL; u32 cmd_op = cmd->cmd_op; u16 q_id = READ_ONCE(ub_src->q_id); u16 tag = READ_ONCE(ub_src->tag); @@ -2422,7 +2422,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, out: pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n", - __func__, cmd_op, tag, ret, io->flags); + __func__, cmd_op, tag, ret, io ? io->flags : 0); return ret; } |