5.15-stable review patch. If anyone has any objections, please let me know.
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From: Christian Lamparter chunkeey@gmail.com
commit da1b9a55ff116cb040528ef664c70a4eec03ae99 upstream.
Robert Morris reported:
|If a malicious USB device pretends to be an Intersil p54 wifi |interface and generates an eeprom_readback message with a large |eeprom->v1.len, p54_rx_eeprom_readback() will copy data from the |message beyond the end of priv->eeprom. | |static void p54_rx_eeprom_readback(struct p54_common *priv, | struct sk_buff *skb) |{ | struct p54_hdr *hdr = (struct p54_hdr *) skb->data; | struct p54_eeprom_lm86 *eeprom = (struct p54_eeprom_lm86 *) hdr->data; | | if (priv->fw_var >= 0x509) { | memcpy(priv->eeprom, eeprom->v2.data, | le16_to_cpu(eeprom->v2.len)); | } else { | memcpy(priv->eeprom, eeprom->v1.data, | le16_to_cpu(eeprom->v1.len)); | } | [...]
The eeprom->v{1,2}.len is set by the driver in p54_download_eeprom(). The device is supposed to provide the same length back to the driver. But yes, it's possible (like shown in the report) to alter the value to something that causes a crash/panic due to overrun.
This patch addresses the issue by adding the size to the common device context, so p54_rx_eeprom_readback no longer relies on possibly tampered values... That said, it also checks if the "firmware" altered the value and no longer copies them.
The one, small saving grace is: Before the driver tries to read the eeprom, it needs to upload >a< firmware. the vendor firmware has a proprietary license and as a reason, it is not present on most distributions by default.
Cc: stable@kernel.org Reported-by: Robert Morris rtm@mit.edu Closes: https://lore.kernel.org/linux-wireless/28782.1747258414@localhost/ Fixes: 7cb770729ba8 ("p54: move eeprom code into common library") Signed-off-by: Christian Lamparter chunkeey@gmail.com Link: https://patch.msgid.link/20250516184107.47794-1-chunkeey@gmail.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wireless/intersil/p54/fwio.c | 2 ++ drivers/net/wireless/intersil/p54/p54.h | 1 + drivers/net/wireless/intersil/p54/txrx.c | 13 +++++++++---- 3 files changed, 12 insertions(+), 4 deletions(-)
--- a/drivers/net/wireless/intersil/p54/fwio.c +++ b/drivers/net/wireless/intersil/p54/fwio.c @@ -233,6 +233,7 @@ int p54_download_eeprom(struct p54_commo
mutex_lock(&priv->eeprom_mutex); priv->eeprom = buf; + priv->eeprom_slice_size = len; eeprom_hdr = skb_put(skb, eeprom_hdr_size + len);
if (priv->fw_var < 0x509) { @@ -255,6 +256,7 @@ int p54_download_eeprom(struct p54_commo ret = -EBUSY; } priv->eeprom = NULL; + priv->eeprom_slice_size = 0; mutex_unlock(&priv->eeprom_mutex); return ret; } --- a/drivers/net/wireless/intersil/p54/p54.h +++ b/drivers/net/wireless/intersil/p54/p54.h @@ -258,6 +258,7 @@ struct p54_common {
/* eeprom handling */ void *eeprom; + size_t eeprom_slice_size; struct completion eeprom_comp; struct mutex eeprom_mutex; }; --- a/drivers/net/wireless/intersil/p54/txrx.c +++ b/drivers/net/wireless/intersil/p54/txrx.c @@ -500,14 +500,19 @@ static void p54_rx_eeprom_readback(struc return ;
if (priv->fw_var >= 0x509) { - memcpy(priv->eeprom, eeprom->v2.data, - le16_to_cpu(eeprom->v2.len)); + if (le16_to_cpu(eeprom->v2.len) != priv->eeprom_slice_size) + return; + + memcpy(priv->eeprom, eeprom->v2.data, priv->eeprom_slice_size); } else { - memcpy(priv->eeprom, eeprom->v1.data, - le16_to_cpu(eeprom->v1.len)); + if (le16_to_cpu(eeprom->v1.len) != priv->eeprom_slice_size) + return; + + memcpy(priv->eeprom, eeprom->v1.data, priv->eeprom_slice_size); }
priv->eeprom = NULL; + priv->eeprom_slice_size = 0; tmp = p54_find_and_unlink_skb(priv, hdr->req_id); dev_kfree_skb_any(tmp); complete(&priv->eeprom_comp);