Re: [PATCH] scsi: target: configfs: bound snprintf return in tg_pt_gp_members_show

"Martin K. Petersen" <[email protected]> Mon, 13 Apr 2026 22:44:26 -0400
Newsgroups org.kernel.vger.target-devel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-scsi
Organization Oracle Corporation
Message-ID <[email protected]>
Greg,

> target_tg_pt_gp_members_show() formats LUN paths with snprintf() into
> a 256-byte stack buffer, then will memcpy cur_len bytes from that
> buffer. snprintf() returns the length the output would have had, which
> can exceed the buffer size when the fabric WWN is long because iSCSI
> IQN names can be up to 223 bytes. The check at the memcpy site only
> guards the destination page write, not the source read, so memcpy()
> will read past the stack buffer and copy adjacent stack contents to
> the sysfs reader, which when CONFIG_FORTIFY_SOURCE is enabled,
> fortify_panic() will be triggered.

Applied to 7.1/scsi-staging, thanks!

-- 
Martin K. Petersen