* [PATCH] hw/scsi/megasas: Fix possible out-of-bounds array access in tracepoints
@ 2020-06-15 7:26 Thomas Huth
2020-06-15 7:35 ` Philippe Mathieu-Daudé
2020-06-15 14:12 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Thomas Huth @ 2020-06-15 7:26 UTC (permalink / raw)
To: qemu-devel, Hannes Reinecke; +Cc: Fam Zheng, Paolo Bonzini, qemu-block
Some tracepoints in megasas.c use a guest-controlled value as an index
into the mfi_frame_desc[] array. Thus a malicious guest could cause an
out-of-bounds error here. Fortunately, the impact is very low since this
can only happen when the corresponding tracepoints have been enabled
before, but the problem should be fixed anyway with a proper check.
Buglink: https://bugs.launchpad.net/qemu/+bug/1882065
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
hw/scsi/megasas.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index af18c88b65..aa930226f8 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -54,10 +54,6 @@
#define MEGASAS_FLAG_USE_QUEUE64 1
#define MEGASAS_MASK_USE_QUEUE64 (1 << MEGASAS_FLAG_USE_QUEUE64)
-static const char *mfi_frame_desc[] = {
- "MFI init", "LD Read", "LD Write", "LD SCSI", "PD SCSI",
- "MFI Doorbell", "MFI Abort", "MFI SMP", "MFI Stop"};
-
typedef struct MegasasCmd {
uint32_t index;
uint16_t flags;
@@ -183,6 +179,20 @@ static void megasas_frame_set_scsi_status(MegasasState *s,
stb_pci_dma(pci, frame + offsetof(struct mfi_frame_header, scsi_status), v);
}
+static inline const char *mfi_frame_desc(unsigned int cmd)
+{
+ static const char *mfi_frame_descs[] = {
+ "MFI init", "LD Read", "LD Write", "LD SCSI", "PD SCSI",
+ "MFI Doorbell", "MFI Abort", "MFI SMP", "MFI Stop"
+ };
+
+ if (cmd < ARRAY_SIZE(mfi_frame_descs)) {
+ return mfi_frame_descs[cmd];
+ }
+
+ return "Unknown";
+}
+
/*
* Context is considered opaque, but the HBA firmware is running
* in little endian mode. So convert it to little endian, too.
@@ -1670,25 +1680,25 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
if (is_logical) {
if (target_id >= MFI_MAX_LD || lun_id != 0) {
trace_megasas_scsi_target_not_present(
- mfi_frame_desc[frame_cmd], is_logical, target_id, lun_id);
+ mfi_frame_desc(frame_cmd), is_logical, target_id, lun_id);
return MFI_STAT_DEVICE_NOT_FOUND;
}
}
sdev = scsi_device_find(&s->bus, 0, target_id, lun_id);
cmd->iov_size = le32_to_cpu(cmd->frame->header.data_len);
- trace_megasas_handle_scsi(mfi_frame_desc[frame_cmd], is_logical,
+ trace_megasas_handle_scsi(mfi_frame_desc(frame_cmd), is_logical,
target_id, lun_id, sdev, cmd->iov_size);
if (!sdev || (megasas_is_jbod(s) && is_logical)) {
trace_megasas_scsi_target_not_present(
- mfi_frame_desc[frame_cmd], is_logical, target_id, lun_id);
+ mfi_frame_desc(frame_cmd), is_logical, target_id, lun_id);
return MFI_STAT_DEVICE_NOT_FOUND;
}
if (cdb_len > 16) {
trace_megasas_scsi_invalid_cdb_len(
- mfi_frame_desc[frame_cmd], is_logical,
+ mfi_frame_desc(frame_cmd), is_logical,
target_id, lun_id, cdb_len);
megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
cmd->frame->header.scsi_status = CHECK_CONDITION;
@@ -1706,7 +1716,7 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
cmd->req = scsi_req_new(sdev, cmd->index, lun_id, cdb, cmd);
if (!cmd->req) {
trace_megasas_scsi_req_alloc_failed(
- mfi_frame_desc[frame_cmd], target_id, lun_id);
+ mfi_frame_desc(frame_cmd), target_id, lun_id);
megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
cmd->frame->header.scsi_status = BUSY;
s->event_count++;
@@ -1751,17 +1761,17 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
}
trace_megasas_handle_io(cmd->index,
- mfi_frame_desc[frame_cmd], target_id, lun_id,
+ mfi_frame_desc(frame_cmd), target_id, lun_id,
(unsigned long)lba_start, (unsigned long)lba_count);
if (!sdev) {
trace_megasas_io_target_not_present(cmd->index,
- mfi_frame_desc[frame_cmd], target_id, lun_id);
+ mfi_frame_desc(frame_cmd), target_id, lun_id);
return MFI_STAT_DEVICE_NOT_FOUND;
}
if (cdb_len > 16) {
trace_megasas_scsi_invalid_cdb_len(
- mfi_frame_desc[frame_cmd], 1, target_id, lun_id, cdb_len);
+ mfi_frame_desc(frame_cmd), 1, target_id, lun_id, cdb_len);
megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
cmd->frame->header.scsi_status = CHECK_CONDITION;
s->event_count++;
@@ -1781,7 +1791,7 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
lun_id, cdb, cmd);
if (!cmd->req) {
trace_megasas_scsi_req_alloc_failed(
- mfi_frame_desc[frame_cmd], target_id, lun_id);
+ mfi_frame_desc(frame_cmd), target_id, lun_id);
megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
cmd->frame->header.scsi_status = BUSY;
s->event_count++;
--
2.18.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] hw/scsi/megasas: Fix possible out-of-bounds array access in tracepoints
2020-06-15 7:26 [PATCH] hw/scsi/megasas: Fix possible out-of-bounds array access in tracepoints Thomas Huth
@ 2020-06-15 7:35 ` Philippe Mathieu-Daudé
2020-06-15 14:12 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-06-15 7:35 UTC (permalink / raw)
To: Thomas Huth, qemu-devel, Hannes Reinecke
Cc: Fam Zheng, Paolo Bonzini, qemu-block
On 6/15/20 9:26 AM, Thomas Huth wrote:
> Some tracepoints in megasas.c use a guest-controlled value as an index
> into the mfi_frame_desc[] array. Thus a malicious guest could cause an
> out-of-bounds error here. Fortunately, the impact is very low since this
> can only happen when the corresponding tracepoints have been enabled
> before, but the problem should be fixed anyway with a proper check.
>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1882065
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
> hw/scsi/megasas.c | 36 +++++++++++++++++++++++-------------
> 1 file changed, 23 insertions(+), 13 deletions(-)
>
> diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
> index af18c88b65..aa930226f8 100644
> --- a/hw/scsi/megasas.c
> +++ b/hw/scsi/megasas.c
> @@ -54,10 +54,6 @@
> #define MEGASAS_FLAG_USE_QUEUE64 1
> #define MEGASAS_MASK_USE_QUEUE64 (1 << MEGASAS_FLAG_USE_QUEUE64)
>
> -static const char *mfi_frame_desc[] = {
> - "MFI init", "LD Read", "LD Write", "LD SCSI", "PD SCSI",
> - "MFI Doorbell", "MFI Abort", "MFI SMP", "MFI Stop"};
> -
> typedef struct MegasasCmd {
> uint32_t index;
> uint16_t flags;
> @@ -183,6 +179,20 @@ static void megasas_frame_set_scsi_status(MegasasState *s,
> stb_pci_dma(pci, frame + offsetof(struct mfi_frame_header, scsi_status), v);
> }
>
> +static inline const char *mfi_frame_desc(unsigned int cmd)
> +{
> + static const char *mfi_frame_descs[] = {
> + "MFI init", "LD Read", "LD Write", "LD SCSI", "PD SCSI",
> + "MFI Doorbell", "MFI Abort", "MFI SMP", "MFI Stop"
> + };
> +
> + if (cmd < ARRAY_SIZE(mfi_frame_descs)) {
> + return mfi_frame_descs[cmd];
> + }
> +
> + return "Unknown";
> +}
> +
> /*
> * Context is considered opaque, but the HBA firmware is running
> * in little endian mode. So convert it to little endian, too.
> @@ -1670,25 +1680,25 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
> if (is_logical) {
> if (target_id >= MFI_MAX_LD || lun_id != 0) {
> trace_megasas_scsi_target_not_present(
> - mfi_frame_desc[frame_cmd], is_logical, target_id, lun_id);
> + mfi_frame_desc(frame_cmd), is_logical, target_id, lun_id);
> return MFI_STAT_DEVICE_NOT_FOUND;
> }
> }
> sdev = scsi_device_find(&s->bus, 0, target_id, lun_id);
>
> cmd->iov_size = le32_to_cpu(cmd->frame->header.data_len);
> - trace_megasas_handle_scsi(mfi_frame_desc[frame_cmd], is_logical,
> + trace_megasas_handle_scsi(mfi_frame_desc(frame_cmd), is_logical,
> target_id, lun_id, sdev, cmd->iov_size);
>
> if (!sdev || (megasas_is_jbod(s) && is_logical)) {
> trace_megasas_scsi_target_not_present(
> - mfi_frame_desc[frame_cmd], is_logical, target_id, lun_id);
> + mfi_frame_desc(frame_cmd), is_logical, target_id, lun_id);
> return MFI_STAT_DEVICE_NOT_FOUND;
> }
>
> if (cdb_len > 16) {
> trace_megasas_scsi_invalid_cdb_len(
> - mfi_frame_desc[frame_cmd], is_logical,
> + mfi_frame_desc(frame_cmd), is_logical,
> target_id, lun_id, cdb_len);
> megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
> cmd->frame->header.scsi_status = CHECK_CONDITION;
> @@ -1706,7 +1716,7 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
> cmd->req = scsi_req_new(sdev, cmd->index, lun_id, cdb, cmd);
> if (!cmd->req) {
> trace_megasas_scsi_req_alloc_failed(
> - mfi_frame_desc[frame_cmd], target_id, lun_id);
> + mfi_frame_desc(frame_cmd), target_id, lun_id);
> megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
> cmd->frame->header.scsi_status = BUSY;
> s->event_count++;
> @@ -1751,17 +1761,17 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
> }
>
> trace_megasas_handle_io(cmd->index,
> - mfi_frame_desc[frame_cmd], target_id, lun_id,
> + mfi_frame_desc(frame_cmd), target_id, lun_id,
> (unsigned long)lba_start, (unsigned long)lba_count);
> if (!sdev) {
> trace_megasas_io_target_not_present(cmd->index,
> - mfi_frame_desc[frame_cmd], target_id, lun_id);
> + mfi_frame_desc(frame_cmd), target_id, lun_id);
> return MFI_STAT_DEVICE_NOT_FOUND;
> }
>
> if (cdb_len > 16) {
> trace_megasas_scsi_invalid_cdb_len(
> - mfi_frame_desc[frame_cmd], 1, target_id, lun_id, cdb_len);
> + mfi_frame_desc(frame_cmd), 1, target_id, lun_id, cdb_len);
> megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
> cmd->frame->header.scsi_status = CHECK_CONDITION;
> s->event_count++;
> @@ -1781,7 +1791,7 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
> lun_id, cdb, cmd);
> if (!cmd->req) {
> trace_megasas_scsi_req_alloc_failed(
> - mfi_frame_desc[frame_cmd], target_id, lun_id);
> + mfi_frame_desc(frame_cmd), target_id, lun_id);
> megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
> cmd->frame->header.scsi_status = BUSY;
> s->event_count++;
>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] hw/scsi/megasas: Fix possible out-of-bounds array access in tracepoints
2020-06-15 7:26 [PATCH] hw/scsi/megasas: Fix possible out-of-bounds array access in tracepoints Thomas Huth
2020-06-15 7:35 ` Philippe Mathieu-Daudé
@ 2020-06-15 14:12 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2020-06-15 14:12 UTC (permalink / raw)
To: Thomas Huth, qemu-devel, Hannes Reinecke; +Cc: Fam Zheng, qemu-block
On 15/06/20 09:26, Thomas Huth wrote:
> Some tracepoints in megasas.c use a guest-controlled value as an index
> into the mfi_frame_desc[] array. Thus a malicious guest could cause an
> out-of-bounds error here. Fortunately, the impact is very low since this
> can only happen when the corresponding tracepoints have been enabled
> before, but the problem should be fixed anyway with a proper check.
>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1882065
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
> hw/scsi/megasas.c | 36 +++++++++++++++++++++++-------------
> 1 file changed, 23 insertions(+), 13 deletions(-)
>
> diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
> index af18c88b65..aa930226f8 100644
> --- a/hw/scsi/megasas.c
> +++ b/hw/scsi/megasas.c
> @@ -54,10 +54,6 @@
> #define MEGASAS_FLAG_USE_QUEUE64 1
> #define MEGASAS_MASK_USE_QUEUE64 (1 << MEGASAS_FLAG_USE_QUEUE64)
>
> -static const char *mfi_frame_desc[] = {
> - "MFI init", "LD Read", "LD Write", "LD SCSI", "PD SCSI",
> - "MFI Doorbell", "MFI Abort", "MFI SMP", "MFI Stop"};
> -
> typedef struct MegasasCmd {
> uint32_t index;
> uint16_t flags;
> @@ -183,6 +179,20 @@ static void megasas_frame_set_scsi_status(MegasasState *s,
> stb_pci_dma(pci, frame + offsetof(struct mfi_frame_header, scsi_status), v);
> }
>
> +static inline const char *mfi_frame_desc(unsigned int cmd)
> +{
> + static const char *mfi_frame_descs[] = {
> + "MFI init", "LD Read", "LD Write", "LD SCSI", "PD SCSI",
> + "MFI Doorbell", "MFI Abort", "MFI SMP", "MFI Stop"
> + };
> +
> + if (cmd < ARRAY_SIZE(mfi_frame_descs)) {
> + return mfi_frame_descs[cmd];
> + }
> +
> + return "Unknown";
> +}
> +
> /*
> * Context is considered opaque, but the HBA firmware is running
> * in little endian mode. So convert it to little endian, too.
> @@ -1670,25 +1680,25 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
> if (is_logical) {
> if (target_id >= MFI_MAX_LD || lun_id != 0) {
> trace_megasas_scsi_target_not_present(
> - mfi_frame_desc[frame_cmd], is_logical, target_id, lun_id);
> + mfi_frame_desc(frame_cmd), is_logical, target_id, lun_id);
> return MFI_STAT_DEVICE_NOT_FOUND;
> }
> }
> sdev = scsi_device_find(&s->bus, 0, target_id, lun_id);
>
> cmd->iov_size = le32_to_cpu(cmd->frame->header.data_len);
> - trace_megasas_handle_scsi(mfi_frame_desc[frame_cmd], is_logical,
> + trace_megasas_handle_scsi(mfi_frame_desc(frame_cmd), is_logical,
> target_id, lun_id, sdev, cmd->iov_size);
>
> if (!sdev || (megasas_is_jbod(s) && is_logical)) {
> trace_megasas_scsi_target_not_present(
> - mfi_frame_desc[frame_cmd], is_logical, target_id, lun_id);
> + mfi_frame_desc(frame_cmd), is_logical, target_id, lun_id);
> return MFI_STAT_DEVICE_NOT_FOUND;
> }
>
> if (cdb_len > 16) {
> trace_megasas_scsi_invalid_cdb_len(
> - mfi_frame_desc[frame_cmd], is_logical,
> + mfi_frame_desc(frame_cmd), is_logical,
> target_id, lun_id, cdb_len);
> megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
> cmd->frame->header.scsi_status = CHECK_CONDITION;
> @@ -1706,7 +1716,7 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
> cmd->req = scsi_req_new(sdev, cmd->index, lun_id, cdb, cmd);
> if (!cmd->req) {
> trace_megasas_scsi_req_alloc_failed(
> - mfi_frame_desc[frame_cmd], target_id, lun_id);
> + mfi_frame_desc(frame_cmd), target_id, lun_id);
> megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
> cmd->frame->header.scsi_status = BUSY;
> s->event_count++;
> @@ -1751,17 +1761,17 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
> }
>
> trace_megasas_handle_io(cmd->index,
> - mfi_frame_desc[frame_cmd], target_id, lun_id,
> + mfi_frame_desc(frame_cmd), target_id, lun_id,
> (unsigned long)lba_start, (unsigned long)lba_count);
> if (!sdev) {
> trace_megasas_io_target_not_present(cmd->index,
> - mfi_frame_desc[frame_cmd], target_id, lun_id);
> + mfi_frame_desc(frame_cmd), target_id, lun_id);
> return MFI_STAT_DEVICE_NOT_FOUND;
> }
>
> if (cdb_len > 16) {
> trace_megasas_scsi_invalid_cdb_len(
> - mfi_frame_desc[frame_cmd], 1, target_id, lun_id, cdb_len);
> + mfi_frame_desc(frame_cmd), 1, target_id, lun_id, cdb_len);
> megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
> cmd->frame->header.scsi_status = CHECK_CONDITION;
> s->event_count++;
> @@ -1781,7 +1791,7 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
> lun_id, cdb, cmd);
> if (!cmd->req) {
> trace_megasas_scsi_req_alloc_failed(
> - mfi_frame_desc[frame_cmd], target_id, lun_id);
> + mfi_frame_desc(frame_cmd), target_id, lun_id);
> megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
> cmd->frame->header.scsi_status = BUSY;
> s->event_count++;
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-06-15 14:13 UTC | newest]
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2020-06-15 7:26 [PATCH] hw/scsi/megasas: Fix possible out-of-bounds array access in tracepoints Thomas Huth
2020-06-15 7:35 ` Philippe Mathieu-Daudé
2020-06-15 14:12 ` Paolo Bonzini
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