Messages in this thread | | | Subject | Re: [PATCH] scsi: core: initialize cmd->cmnd before it is used | From | Bart Van Assche <> | Date | Mon, 1 Nov 2021 13:20:19 -0700 |
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On 11/1/21 1:13 PM, Tadeusz Struk wrote: > On 11/1/21 13:06, Bart Van Assche wrote: >> This patch is a duplicate and has been posted before. >> >> Please take a look at https://lore.kernel.org/linux-scsi/20210904064534.1919476-1-qiulaibin@huawei.com/. >> From the replies to that email: >> "> Thinking further about this: is there any code left that depends on >> > scsi_setup_scsi_cmnd() setting cmd->cmd_len? Can the cmd->cmd_len >> > assignment be removed from scsi_setup_scsi_cmnd()? >> >> cmd_len should never be 0 now, so I think we can remove it." > > Thanks for quick response, but I'm not sure if statement > "cmd_len should never be 0 now" is correct, because the cmd_len is > in fact equal to 0 here and this BUG can be triggered on mainline, 5.14, > and 5.10 stable kernels.
(+Doug Gilbert)
One of the functions in the call stack in the first message of this email thread is sg_io(). I am not aware of any documentation that specifies whether it is valid to set cmd_len in the sg_io header to zero. My opinion is that the SG_IO implementation should either reject cmd_len == 0 or set cmd_len to a valid value if it is zero.
Bart.
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