Bug 2516481 (CVE-2026-72441)

Summary: CVE-2026-72441 kernel: ieee802154: fix kernel-infoleak in dgram_recvmsg()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's IEEE 802.15.4 (Wireless Personal Area Networks) networking component. This vulnerability allows a local user to expose sensitive kernel memory. The issue arises because a specific field (pan_id) in a network address structure is not properly cleared, leading to uninitialized data being copied to user space. This could result in the disclosure of potentially sensitive information from the kernel's memory.
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Description OSIDB Bzimport 2026-08-15 06:14:46 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ieee802154: fix kernel-infoleak in dgram_recvmsg()

KMSAN reported a kernel-infoleak in move_addr_to_user():

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user
include/linux/instrumented.h:131 [inline]
BUG: KMSAN: kernel-infoleak in _inline_copy_to_user
include/linux/uaccess.h:205 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xcc/0x120
lib/usercopy.c:26
 instrument_copy_to_user include/linux/instrumented.h:131 [inline]
 _inline_copy_to_user include/linux/uaccess.h:205 [inline]
 _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:236 [inline]
 move_addr_to_user+0x2e7/0x440 net/socket.c:302
 ____sys_recvmsg+0x232/0x610 net/socket.c:2925
 ...
 Uninit was stored to memory at:
 ieee802154_addr_to_sa include/net/ieee802154_netdev.h:369 [inline]
 dgram_recvmsg+0xa09/0xbe0 net/ieee802154/socket.c:739

The issue occurs because the `pan_id` field of `struct ieee802154_addr`
is left uninitialized when the address mode is `IEEE802154_ADDR_NONE`.
The execution flow is as follows:

1. `__ieee802154_rx_handle_packet()` declares a local `struct
ieee802154_hdr hdr` on the stack.
2. `ieee802154_hdr_pull()` calls `ieee802154_hdr_get_addr()` to parse
the source and destination addresses into this structure.
3. If the address mode is `IEEE802154_ADDR_NONE`,
`ieee802154_hdr_get_addr()` previously only set the `mode` field,
leaving the `pan_id` field containing uninitialized stack memory.
4. This uninitialized `pan_id` is later copied into a `struct
sockaddr_ieee802154` in `dgram_recvmsg()` via `ieee802154_addr_to_sa()`.
5. Finally, `move_addr_to_user()` copies the socket address structure to
user space, leaking the uninitialized bytes.

Fix this by using `memset` to zero out the address structure in
`ieee802154_hdr_get_addr()` when the mode is `IEEE802154_ADDR_NONE`.
Comment 1 gkamathe 2026-08-18 13:24:26 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081529-CVE-2026-72441-b58c@gregkh/T