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author | mav <mav@FreeBSD.org> | 2015-10-05 09:26:00 +0000 |
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committer | mav <mav@FreeBSD.org> | 2015-10-05 09:26:00 +0000 |
commit | c45abe20442cc1352a834efd7d05f664ce23c2d6 (patch) | |
tree | 58c092acad255217c070fe4bceed452bfff974a8 | |
parent | 2ddbc805cd7d34853759754a0c0dc1ce1694b1a8 (diff) | |
download | FreeBSD-src-c45abe20442cc1352a834efd7d05f664ce23c2d6.zip FreeBSD-src-c45abe20442cc1352a834efd7d05f664ce23c2d6.tar.gz |
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.
-rw-r--r-- | sys/cam/ctl/ctl_backend_block.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/sys/cam/ctl/ctl_backend_block.c b/sys/cam/ctl/ctl_backend_block.c index c80304e..aa794a6 100644 --- a/sys/cam/ctl/ctl_backend_block.c +++ b/sys/cam/ctl/ctl_backend_block.c @@ -635,8 +635,8 @@ ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun, 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_block_lun *be_lun, 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; |