diff options
| author | Shmulik Cohen <anuk909@gmail.com> | 2026-08-12 22:04:12 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2026-09-04 10:12:29 +0200 |
| commit | c46cfaf8db42de0806076139fb40744d23041377 (patch) | |
| tree | cd5f6942a1f6eb6d50e1c0d6093090e523f6fe40 /drivers | |
| parent | adb7118b7d2cfd7e8213c17d7d2829f353017754 (diff) | |
wifi: ipw2x00: bound management frame length to the receive buffer
Both management receive paths establish a lower bound on the frame
length and no upper bound, even though the length originates from the
device.
ipw2100_corruption_check() returns 0 without inspecting frame_size for
management frames, and __ipw2100_rx_process() only rejects a frame
smaller than the three-address header, so any reported size up to the
u32 limit reaches libipw_rx_mgt() against a receive allocation of
IPW_RX_NIC_BUFFER_LENGTH bytes. Check frame_size itself rather than
stats.len, which is a u16: a size of 65566 truncates to 30 on
assignment and would pass a check made afterwards.
ipw_rx() likewise only rejects a frame shorter than the header length.
Bound it against the DMA mapped receive buffer. The size passed to
alloc_skb() is rounded up by the allocator, so skb_tailroom() can
exceed IPW_RX_BUF_SIZE and is not a usable bound here; the existing
uses of that idiom in the data paths are too permissive for the same
reason.
libipw then hands the remainder to libipw_parse_info_param(), which
walks information elements for as long as the length allows, so an
over-long reported length reads past the receive buffer without any
wraparound being involved.
The length is device-reported, so per
Documentation/process/threat-model.rst this is a robustness fix rather
than a vulnerability.
Found by an AI-assisted review of length arithmetic in management frame
parsers. Compile-tested only for these two hunks; I do not have the
hardware, so they are not tested on a real device.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Shmulik Cohen <anuk909@gmail.com>
Link: https://patch.msgid.link/20260812190412.18333-4-anuk909@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/wireless/intel/ipw2x00/ipw2100.c | 4 | ||||
| -rw-r--r-- | drivers/net/wireless/intel/ipw2x00/ipw2200.c | 9 |
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/net/wireless/intel/ipw2x00/ipw2100.c b/drivers/net/wireless/intel/ipw2x00/ipw2100.c index 2b8a23865bfb..43b4e432956b 100644 --- a/drivers/net/wireless/intel/ipw2x00/ipw2100.c +++ b/drivers/net/wireless/intel/ipw2x00/ipw2100.c @@ -2712,7 +2712,9 @@ static void __ipw2100_rx_process(struct ipw2100_priv *priv) break; } #endif - if (stats.len < sizeof(struct libipw_hdr_3addr)) + if (sq->drv[i].frame_size < + sizeof(struct libipw_hdr_3addr) || + sq->drv[i].frame_size > IPW_RX_NIC_BUFFER_LENGTH) break; switch (WLAN_FC_GET_TYPE(le16_to_cpu(u->rx_data.header.frame_ctl))) { case IEEE80211_FTYPE_MGMT: diff --git a/drivers/net/wireless/intel/ipw2x00/ipw2200.c b/drivers/net/wireless/intel/ipw2x00/ipw2200.c index 4bc9bb406e8e..8249d493ee22 100644 --- a/drivers/net/wireless/intel/ipw2x00/ipw2200.c +++ b/drivers/net/wireless/intel/ipw2x00/ipw2200.c @@ -8322,6 +8322,15 @@ static void ipw_rx(struct ipw_priv *priv) break; } + if (unlikely(le16_to_cpu(pkt->u.frame.length) > + IPW_RX_BUF_SIZE - + IPW_RX_FRAME_SIZE)) { + IPW_DEBUG_DROP("Received oversized packet. Dropping.\n"); + priv->net_dev->stats.rx_errors++; + priv->wstats.discard.misc++; + break; + } + switch (WLAN_FC_GET_TYPE (le16_to_cpu(header->frame_ctl))) { |