In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: limit injected antenna index in ieee80211_parse_tx_radiotap
When parsing the radiotap header of an injected frame,
ieee80211_parse_tx_radiotap() uses the IEEE80211_RADIOTAP_ANTENNA value
directly as a shift count:
info->control.antennas |= BIT(*iterator.this_arg);
*iterator.this_arg is an 8-bit value taken straight from the frame
supplied by userspace, so BIT() can be asked to shift by up to 255. That
is undefined behaviour on the unsigned long and is reported by UBSAN:
UBSAN: shift-out-of-bounds in net/mac80211/tx.c:2174:30
shift exponent 235 is too large for 64-bit type 'unsigned long'
Call Trace:
ieee80211_parse_tx_radiotap+0xadb/0x1950 net/mac80211/tx.c:2174
ieee80211_monitor_start_xmit+0xb1f/0x1250 net/mac80211/tx.c:2451
...
packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3109
info->control.antennas is a 2-bit bitmap (u8 antennas:2), so only antenna
indices 0 and 1 can ever be represented. Ignore any larger value instead
of shifting out of bounds.
wifi: mac80211: limit injected antenna index in ieee80211_parse_tx_radiotap
When parsing the radiotap header of an injected frame,
ieee80211_parse_tx_radiotap() uses the IEEE80211_RADIOTAP_ANTENNA value
directly as a shift count:
info->control.antennas |= BIT(*iterator.this_arg);
*iterator.this_arg is an 8-bit value taken straight from the frame
supplied by userspace, so BIT() can be asked to shift by up to 255. That
is undefined behaviour on the unsigned long and is reported by UBSAN:
UBSAN: shift-out-of-bounds in net/mac80211/tx.c:2174:30
shift exponent 235 is too large for 64-bit type 'unsigned long'
Call Trace:
ieee80211_parse_tx_radiotap+0xadb/0x1950 net/mac80211/tx.c:2174
ieee80211_monitor_start_xmit+0xb1f/0x1250 net/mac80211/tx.c:2451
...
packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3109
info->control.antennas is a 2-bit bitmap (u8 antennas:2), so only antenna
indices 0 and 1 can ever be represented. Ignore any larger value instead
of shifting out of bounds.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||
| Linux | Linux | affected |
|
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 19 Jul 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: limit injected antenna index in ieee80211_parse_tx_radiotap When parsing the radiotap header of an injected frame, ieee80211_parse_tx_radiotap() uses the IEEE80211_RADIOTAP_ANTENNA value directly as a shift count: info->control.antennas |= BIT(*iterator.this_arg); *iterator.this_arg is an 8-bit value taken straight from the frame supplied by userspace, so BIT() can be asked to shift by up to 255. That is undefined behaviour on the unsigned long and is reported by UBSAN: UBSAN: shift-out-of-bounds in net/mac80211/tx.c:2174:30 shift exponent 235 is too large for 64-bit type 'unsigned long' Call Trace: ieee80211_parse_tx_radiotap+0xadb/0x1950 net/mac80211/tx.c:2174 ieee80211_monitor_start_xmit+0xb1f/0x1250 net/mac80211/tx.c:2451 ... packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3109 info->control.antennas is a 2-bit bitmap (u8 antennas:2), so only antenna indices 0 and 1 can ever be represented. Ignore any larger value instead of shifting out of bounds. | |
| Title | wifi: mac80211: limit injected antenna index in ieee80211_parse_tx_radiotap | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-19T14:18:38.426Z
Reserved: 2026-07-19T07:54:57.017Z
Link: CVE-2026-63869
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
No weakness.