6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings ben@decadent.org.uk
[ Upstream commit d4cdc46ca16a5c78b36c5b9b6ad8cac09d6130a0 ]
iwlegacy uses command buffers with a payload size of 320 bytes (default) or 4092 bytes (huge). The struct il_device_cmd type describes the default buffers and there is no separate type describing the huge buffers.
The il_enqueue_hcmd() function works with both default and huge buffers, and has a memcpy() to the buffer payload. The size of this copy may exceed 320 bytes when using a huge buffer, which now results in a run-time warning:
memcpy: detected field-spanning write (size 1014) of single field "&out_cmd->cmd.payload" at drivers/net/wireless/intel/iwlegacy/common.c:3170 (size 320)
To fix this:
- Define a new struct type for huge buffers, with a correctly sized payload field - When using a huge buffer in il_enqueue_hcmd(), cast the command buffer pointer to that type when looking up the payload field
Reported-by: Martin-Éric Racine martin-eric.racine@iki.fi References: https://bugs.debian.org/1062421 References: https://bugzilla.kernel.org/show_bug.cgi?id=219124 Signed-off-by: Ben Hutchings ben@decadent.org.uk Fixes: 54d9469bc515 ("fortify: Add run-time WARN for cross-field memcpy()") Tested-by: Martin-Éric Racine martin-eric.racine@iki.fi Tested-by: Brandon Nielsen nielsenb@jetfuse.net Acked-by: Stanislaw Gruszka stf_xl@wp.pl Signed-off-by: Kalle Valo kvalo@kernel.org Link: https://patch.msgid.link/ZuIhQRi/791vlUhE@decadent.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/intel/iwlegacy/common.c | 13 ++++++++++++- drivers/net/wireless/intel/iwlegacy/common.h | 12 ++++++++++++ 2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c index 96002121bb8b2..9fa38221c4311 100644 --- a/drivers/net/wireless/intel/iwlegacy/common.c +++ b/drivers/net/wireless/intel/iwlegacy/common.c @@ -3119,6 +3119,7 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd) struct il_cmd_meta *out_meta; dma_addr_t phys_addr; unsigned long flags; + u8 *out_payload; u32 idx; u16 fix_size;
@@ -3154,6 +3155,16 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd) out_cmd = txq->cmd[idx]; out_meta = &txq->meta[idx];
+ /* The payload is in the same place in regular and huge + * command buffers, but we need to let the compiler know when + * we're using a larger payload buffer to avoid "field- + * spanning write" warnings at run-time for huge commands. + */ + if (cmd->flags & CMD_SIZE_HUGE) + out_payload = ((struct il_device_cmd_huge *)out_cmd)->cmd.payload; + else + out_payload = out_cmd->cmd.payload; + if (WARN_ON(out_meta->flags & CMD_MAPPED)) { spin_unlock_irqrestore(&il->hcmd_lock, flags); return -ENOSPC; @@ -3167,7 +3178,7 @@ il_enqueue_hcmd(struct il_priv *il, struct il_host_cmd *cmd) out_meta->callback = cmd->callback;
out_cmd->hdr.cmd = cmd->id; - memcpy(&out_cmd->cmd.payload, cmd->data, cmd->len); + memcpy(out_payload, cmd->data, cmd->len);
/* At this point, the out_cmd now has all of the incoming cmd * information */ diff --git a/drivers/net/wireless/intel/iwlegacy/common.h b/drivers/net/wireless/intel/iwlegacy/common.h index 69687fcf963fc..027dae5619a37 100644 --- a/drivers/net/wireless/intel/iwlegacy/common.h +++ b/drivers/net/wireless/intel/iwlegacy/common.h @@ -560,6 +560,18 @@ struct il_device_cmd {
#define TFD_MAX_PAYLOAD_SIZE (sizeof(struct il_device_cmd))
+/** + * struct il_device_cmd_huge + * + * For use when sending huge commands. + */ +struct il_device_cmd_huge { + struct il_cmd_header hdr; /* uCode API */ + union { + u8 payload[IL_MAX_CMD_SIZE - sizeof(struct il_cmd_header)]; + } __packed cmd; +} __packed; + struct il_host_cmd { const void *data; unsigned long reply_page;