CVE-2026-64061
Description
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix early put of sink folio in netfs_read_gaps()
Fix netfs_read_gaps() to release the sink page it uses after waiting for
the request to complete. The way the sink page is used is that an
ITER_BVEC-class iterator is created that has the gaps from the target folio
at either end, but has the sink page tiled over the middle so that a single
read op can fill in both gaps.
The bug was found by KASAN detecting a UAF on the generic/075 xfstest in
the cifsd kernel thread that handles reception of data from the TCP socket:
BUG: KASAN: use-after-free in _copy_to_iter+0x48a/0xa20
Write of size 885 at addr ffff888107f92000 by task cifsd/1285
CPU: 2 UID: 0 PID: 1285 Comm: cifsd Not tainted 7.0.0 #6 PREEMPT(lazy)
Call Trace:
dump_stack_lvl+0x5d/0x80
print_report+0x17f/0x4f1
kasan_report+0x100/0x1e0
kasan_check_range+0x10f/0x1e0
__asan_memcpy+0x3c/0x60
_copy_to_iter+0x48a/0xa20
__skb_datagram_iter+0x2c9/0x430
skb_copy_datagram_iter+0x6e/0x160
tcp_recvmsg_locked+0xce0/0x1130
tcp_recvmsg+0xeb/0x300
inet_recvmsg+0xcf/0x3a0
sock_recvmsg+0xea/0x100
cifs_readv_from_socket+0x3a6/0x4d0 [cifs]
cifs_read_iter_from_socket+0xdd/0x130 [cifs]
cifs_readv_receive+0xaad/0xb10 [cifs]
cifs_demultiplex_thread+0x1148/0x1740 [cifs]
kthread+0x1cf/0x210
Metadata
Severity & Metrics
No CVSS data available.
Affected products (2)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| Linux | Linux | — | ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 2a39d49c8d97df8cb8fa80c10859bc1ba7358c6b, ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < d4f4bc87c76511cf2532448b0fa40c25e894bd7d, ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 412e8bad48967fd34295866636c028befd27d8b9, ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 3e5dd91b87a8b1450217b56a336bee315f40da7d |
| Linux | Linux | — | 6.12, 0 < 6.12, 6.12.92 ≤ 6.12.*, 6.18.34 ≤ 6.18.* … |
References (4)