Date: Mon, 5 Oct 2015 09:26:00 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r288764 - stable/10/sys/cam/ctl Message-ID: <201510050926.t959Q04r043166@repo.freebsd.org>
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Author: mav Date: Mon Oct 5 09:26:00 2015 New Revision: 288764 URL: https://svnweb.freebsd.org/changeset/base/288764 Log: MFC r287875: 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: stable/10/sys/cam/ctl/ctl_backend_block.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/cam/ctl/ctl_backend_block.c ============================================================================== --- stable/10/sys/cam/ctl/ctl_backend_block.c Mon Oct 5 09:25:04 2015 (r288763) +++ stable/10/sys/cam/ctl/ctl_backend_block.c Mon Oct 5 09:26:00 2015 (r288764) @@ -635,8 +635,8 @@ 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"); @@ -697,6 +697,22 @@ 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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