* [Qemu-devel] [PATCH] SCSI improved LBA-out-of-range checks @ 2012-07-12 6:52 Ronnie Sahlberg 2012-07-12 6:52 ` [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify Ronnie Sahlberg 0 siblings, 1 reply; 5+ messages in thread From: Ronnie Sahlberg @ 2012-07-12 6:52 UTC (permalink / raw) To: pbonzini, qemu-devel Paolo, List Please find a small patch to the scsi emulation. This patch improves the checkign that the requested lbas are all available. We check both that lba+len is not going past the end of the device but also if lba+len < lba This second condition could occur for deviously crafted scsi packets where lba is set to 0xffffffffffffffff and len is set to 2 in which case lba+len would wrap to 1 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify 2012-07-12 6:52 [Qemu-devel] [PATCH] SCSI improved LBA-out-of-range checks Ronnie Sahlberg @ 2012-07-12 6:52 ` Ronnie Sahlberg 2012-07-12 7:04 ` Paolo Bonzini 0 siblings, 1 reply; 5+ messages in thread From: Ronnie Sahlberg @ 2012-07-12 6:52 UTC (permalink / raw) To: pbonzini, qemu-devel; +Cc: Ronnie Sahlberg Improve the tests for the LBA to cover more cases, the new test looks like this if (r->req.cmd.lba > r->req.cmd.lba + len || r->req.cmd.lba + len > s->qdev.max_lba) { For the 16 byte opcodes, the lba is a uint64, so the first check is to make sure that we do not wrap. For example if an opcode would specify the LBA:0xffffffffffffffff and LEN:2 then lba+len would wrap to 1. The second part of the test is to verify that ALL requested blocks are available, not just the first one. Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> --- hw/scsi-disk.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index b2f3c0c..40c05de 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -1558,7 +1558,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) if (r->req.cmd.buf[1] & 0xe0) { goto fail; } - if (r->req.cmd.lba > s->qdev.max_lba) { + if (r->req.cmd.lba > r->req.cmd.lba + len + || r->req.cmd.lba + len > s->qdev.max_lba) { goto illegal_lba; } r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); @@ -1581,7 +1582,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) if (r->req.cmd.buf[1] & 0xe0) { goto fail; } - if (r->req.cmd.lba > s->qdev.max_lba) { + if (r->req.cmd.lba > r->req.cmd.lba + len + || r->req.cmd.lba + len > s->qdev.max_lba) { goto illegal_lba; } r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); -- 1.7.3.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify 2012-07-12 6:52 ` [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify Ronnie Sahlberg @ 2012-07-12 7:04 ` Paolo Bonzini 2012-07-12 7:06 ` ronnie sahlberg 0 siblings, 1 reply; 5+ messages in thread From: Paolo Bonzini @ 2012-07-12 7:04 UTC (permalink / raw) To: Ronnie Sahlberg; +Cc: qemu-devel Il 12/07/2012 08:52, Ronnie Sahlberg ha scritto: > Improve the tests for the LBA to cover more cases, the new test looks like this > if (r->req.cmd.lba > r->req.cmd.lba + len > || r->req.cmd.lba + len > s->qdev.max_lba) { > > For the 16 byte opcodes, the lba is a uint64, so the first check is to make sure that we do not wrap. > For example if an opcode would specify the LBA:0xffffffffffffffff and LEN:2 > then lba+len would wrap to 1. > > The second part of the test is to verify that ALL requested blocks are available, not just the first one. Fixed code style for || and applied to scsi-next. Thanks! Paolo > Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> > --- > hw/scsi-disk.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c > index b2f3c0c..40c05de 100644 > --- a/hw/scsi-disk.c > +++ b/hw/scsi-disk.c > @@ -1558,7 +1558,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) > if (r->req.cmd.buf[1] & 0xe0) { > goto fail; > } > - if (r->req.cmd.lba > s->qdev.max_lba) { > + if (r->req.cmd.lba > r->req.cmd.lba + len > + || r->req.cmd.lba + len > s->qdev.max_lba) { > goto illegal_lba; > } > r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); > @@ -1581,7 +1582,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) > if (r->req.cmd.buf[1] & 0xe0) { > goto fail; > } > - if (r->req.cmd.lba > s->qdev.max_lba) { > + if (r->req.cmd.lba > r->req.cmd.lba + len > + || r->req.cmd.lba + len > s->qdev.max_lba) { > goto illegal_lba; > } > r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify 2012-07-12 7:04 ` Paolo Bonzini @ 2012-07-12 7:06 ` ronnie sahlberg 2012-07-12 7:15 ` Paolo Bonzini 0 siblings, 1 reply; 5+ messages in thread From: ronnie sahlberg @ 2012-07-12 7:06 UTC (permalink / raw) To: Paolo Bonzini; +Cc: qemu-devel Sorry, there is a bug in it. Can you change it to : || r->req.cmd.lba + len > s->qdev.max_lba + 1) { or else the last lba of the device will be flagged as out of range. On Thu, Jul 12, 2012 at 5:04 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > Il 12/07/2012 08:52, Ronnie Sahlberg ha scritto: >> Improve the tests for the LBA to cover more cases, the new test looks like this >> if (r->req.cmd.lba > r->req.cmd.lba + len >> || r->req.cmd.lba + len > s->qdev.max_lba) { >> >> For the 16 byte opcodes, the lba is a uint64, so the first check is to make sure that we do not wrap. >> For example if an opcode would specify the LBA:0xffffffffffffffff and LEN:2 >> then lba+len would wrap to 1. >> >> The second part of the test is to verify that ALL requested blocks are available, not just the first one. > > Fixed code style for || and applied to scsi-next. > > Thanks! > > Paolo > >> Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> >> --- >> hw/scsi-disk.c | 6 ++++-- >> 1 files changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c >> index b2f3c0c..40c05de 100644 >> --- a/hw/scsi-disk.c >> +++ b/hw/scsi-disk.c >> @@ -1558,7 +1558,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) >> if (r->req.cmd.buf[1] & 0xe0) { >> goto fail; >> } >> - if (r->req.cmd.lba > s->qdev.max_lba) { >> + if (r->req.cmd.lba > r->req.cmd.lba + len >> + || r->req.cmd.lba + len > s->qdev.max_lba) { >> goto illegal_lba; >> } >> r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); >> @@ -1581,7 +1582,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) >> if (r->req.cmd.buf[1] & 0xe0) { >> goto fail; >> } >> - if (r->req.cmd.lba > s->qdev.max_lba) { >> + if (r->req.cmd.lba > r->req.cmd.lba + len >> + || r->req.cmd.lba + len > s->qdev.max_lba) { >> goto illegal_lba; >> } >> r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); >> > > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify 2012-07-12 7:06 ` ronnie sahlberg @ 2012-07-12 7:15 ` Paolo Bonzini 0 siblings, 0 replies; 5+ messages in thread From: Paolo Bonzini @ 2012-07-12 7:15 UTC (permalink / raw) To: ronnie sahlberg; +Cc: qemu-devel Il 12/07/2012 09:06, ronnie sahlberg ha scritto: > Sorry, there is a bug in it. > > Can you change it to : > || r->req.cmd.lba + len > s->qdev.max_lba + 1) { > > or else the last lba of the device will be flagged as out of range. Yes, done that already. Can you add a test for the last LBA to your testsuite? Paolo ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-07-12 7:16 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-07-12 6:52 [Qemu-devel] [PATCH] SCSI improved LBA-out-of-range checks Ronnie Sahlberg 2012-07-12 6:52 ` [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify Ronnie Sahlberg 2012-07-12 7:04 ` Paolo Bonzini 2012-07-12 7:06 ` ronnie sahlberg 2012-07-12 7:15 ` Paolo Bonzini
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).