+-- On Fri, 9 Aug 2019, P J P wrote --+ | From: Prasad J Pandit <p...@fedoraproject.org> | | When executing script in lsi_execute_script(), the LSI scsi | adapter emulator advances 's->dsp' index to read next opcode. | This can lead to an infinite loop if the next opcode is empty. | Exit such loop after reading 10k empty opcodes. | | Reported-by: Bugs SysSec <bugs-sys...@rub.de> | Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> | --- | hw/scsi/lsi53c895a.c | 11 ++++++++++- | 1 file changed, 10 insertions(+), 1 deletion(-) | | Update v3: raise an illegal instruction interrupt and exit | -> https://lists.gnu.org/archive/html/qemu-devel/2019-08/msg01427.html | | diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c | index 10468c1ec1..e703ef4c9d 100644 | --- a/hw/scsi/lsi53c895a.c | +++ b/hw/scsi/lsi53c895a.c | @@ -185,6 +185,9 @@ static const char *names[] = { | /* Flag set if this is a tagged command. */ | #define LSI_TAG_VALID (1 << 16) | | +/* Maximum instructions to process. */ | +#define LSI_MAX_INSN 10000 | + | typedef struct lsi_request { | SCSIRequest *req; | uint32_t tag; | @@ -1132,7 +1135,13 @@ static void lsi_execute_script(LSIState *s) | | s->istat1 |= LSI_ISTAT1_SRUN; | again: | - insn_processed++; | + if (++insn_processed > LSI_MAX_INSN) { | + trace_lsi_execute_script_tc_illegal(); | + lsi_script_dma_interrupt(s, LSI_DSTAT_IID); | + lsi_disconnect(s); | + trace_lsi_execute_script_stop(); | + return; | + } | insn = read_dword(s, s->dsp); | if (!insn) { | /* If we receive an empty opcode increment the DSP by 4 bytes |
Ping...?! -- Prasad J Pandit / Red Hat Product Security Team 47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F