Commit 64dcbde7 authored by Junrui Luo's avatar Junrui Luo Committed by Jakub Kicinski
Browse files

bnxt_en: fix OOB access in DBG_BUF_PRODUCER async event handler 



The ASYNC_EVENT_CMPL_EVENT_ID_DBG_BUF_PRODUCER handler in
bnxt_async_event_process() uses a firmware-supplied 'type' field
directly as an index into bp->bs_trace[] without bounds validation.

The 'type' field is a 16-bit value extracted from DMA-mapped completion
ring memory that the NIC writes directly to host RAM. A malicious or
compromised NIC can supply any value from 0 to 65535, causing an
out-of-bounds access into kernel heap memory.

The bnxt_bs_trace_check_wrap() call then dereferences bs_trace->magic_byte
and writes to bs_trace->last_offset and bs_trace->wrapped, leading to
kernel memory corruption or a crash.

Fix by adding a bounds check and defining BNXT_TRACE_MAX as
DBG_LOG_BUFFER_FLUSH_REQ_TYPE_ERR_QPC_TRACE + 1 to cover all currently
defined firmware trace types (0x0 through 0xc).

Fixes: 84fcd944 ("bnxt_en: Manage the FW trace context memory")
Reported-by: default avatarYuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJunrui Luo <moonafterrain@outlook.com>
Reviewed-by: default avatarMichael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/SYBPR01MB7881A253A1C9775D277F30E9AF42A@SYBPR01MB7881.ausprd01.prod.outlook.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 069c8f5a

drivers/net/ethernet/broadcom/bnxt/bnxt.c

+2 −0
Original line number Diff line number Diff line
@@ -2929,6 +2929,8 @@ static int bnxt_async_event_process(struct bnxt *bp, 
		u16 type = (u16)BNXT_EVENT_BUF_PRODUCER_TYPE(data1);

		u32 offset =  BNXT_EVENT_BUF_PRODUCER_OFFSET(data2);



		if (type >= ARRAY_SIZE(bp->bs_trace))

			goto async_event_process_exit;

		bnxt_bs_trace_check_wrap(&bp->bs_trace[type], offset);

		goto async_event_process_exit;

	}

drivers/net/ethernet/broadcom/bnxt/bnxt.h

+1 −1
Original line number Diff line number Diff line
@@ -2146,7 +2146,7 @@ enum board_idx { 
};



#define BNXT_TRACE_BUF_MAGIC_BYTE ((u8)0xbc)

#define BNXT_TRACE_MAX 11

#define BNXT_TRACE_MAX (DBG_LOG_BUFFER_FLUSH_REQ_TYPE_ERR_QPC_TRACE + 1)



struct bnxt_bs_trace_info {

	u8 *magic_byte;