Date: Wed, 16 Sep 2015 21:43:51 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r287875 - head/sys/cam/ctl Message-ID: <201509162143.t8GLhpOf011472@repo.freebsd.org>
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Author: mav Date: Wed Sep 16 21:43:51 2015 New Revision: 287875 URL: https://svnweb.freebsd.org/changeset/base/287875 Log: Fix reading after end of file for file-backed LUNs. If backing file is smaller then the LUN size, we have to explicitly clear the rest of the buffer to not leak some random data from previous I/Os. Modified: head/sys/cam/ctl/ctl_backend_block.c Modified: head/sys/cam/ctl/ctl_backend_block.c ============================================================================== --- head/sys/cam/ctl/ctl_backend_block.c Wed Sep 16 21:42:33 2015 (r287874) +++ head/sys/cam/ctl/ctl_backend_block.c Wed Sep 16 21:43:51 2015 (r287875) @@ -632,8 +632,8 @@ ctl_be_block_dispatch_file(struct ctl_be union ctl_io *io; struct uio xuio; struct iovec *xiovec; - int flags; - int error, i; + size_t s; + int error, flags, i; DPRINTF("entered\n"); @@ -694,6 +694,22 @@ ctl_be_block_dispatch_file(struct ctl_be VOP_UNLOCK(be_lun->vn, 0); SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0); + if (error == 0 && xuio.uio_resid > 0) { + /* + * If we red less then requested (EOF), then + * we should clean the rest of the buffer. + */ + s = beio->io_len - xuio.uio_resid; + for (i = 0; i < beio->num_segs; i++) { + if (s >= beio->sg_segs[i].len) { + s -= beio->sg_segs[i].len; + continue; + } + bzero((uint8_t *)beio->sg_segs[i].addr + s, + beio->sg_segs[i].len - s); + s = 0; + } + } } else { struct mount *mountpoint; int lock_flags;
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