cbcvebase.
CVE-2024-44935
published 2024-08-26

CVE-2024-44935: In the Linux kernel, the following vulnerability has been resolved: sctp: Fix null-ptr-deref in reuseport_add_sock(). syzbot reported a null-ptr-deref while…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.23%
13.6th percentile
In the Linux kernel, the following vulnerability has been resolved: sctp: Fix null-ptr-deref in reuseport_add_sock(). syzbot reported a null-ptr-deref while accessing sk2->sk_reuseport_cb in reuseport_add_sock(). [0] The repro first creates a listener with SO_REUSEPORT. Then, it creates another listener on the same port and concurrently closes the first listener. The second listen() calls reuseport_add_sock() with the first listener as sk2, where sk2->sk_reuseport_cb is not expected to be cleared concurrently, but the close() does clear it by reuseport_detach_sock(). The problem is SCTP does not properly synchronise reuseport_alloc(), reuseport_add_sock(), and reuseport_detach_sock(). The caller of reuseport_alloc() and reuseport_{add,detach}_sock() must provide synchronisation for sockets that are classified into the same reuseport group. Otherwise, such sockets form multiple identical reuseport groups, and all groups except one would be silently dead. 1. Two sockets call listen() concurrently 2. No socket in the same group found in sctp_ep_hashtable[] 3. Two sockets call reuseport_alloc() and form two reuseport groups 4. Only one group hit first in __sctp_rcv_lookup_endpoint() receives incoming packets Also, the reported null-ptr-deref could occur. TCP/UDP guarantees that would not happen by holding the hash bucket lock. Let's apply the locking strategy to __sctp_hash_endpoint() and __sctp_unhash_endpoint(). [0]: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 UID: 0 PID: 10230 Comm: syz-executor119 Not tainted 6.10.0-syzkaller-12585-g301927d2d2eb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:reuseport_add_sock+0x27e/0x5e0 net/core/sock_reuseport.c:350 Code: 00 0f b7 5d 00 bf 01 00 00 00 89 de e8 1b a4 ff f7 83 fb 01 0f 85 a3 01 00 00 e8 6d a0 ff f7

Affected

28 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.106-1 (bookworm)linux 6.1.106-1 (bookworm)
debianlinux-6.1< linux 6.1.106-1 (bookworm)linux 6.1.106-1 (bookworm)
linuxlinux
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < c9b3fc4f157867e858734e31022ebee8a24f0de7c9b3fc4f157867e858734e31022ebee8a24f0de7
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < 52319d9d2f522ed939af31af70f8c3a0f0f67e6c52319d9d2f522ed939af31af70f8c3a0f0f67e6c
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < 54b303d8f9702b8ab618c5032fae886b1635692854b303d8f9702b8ab618c5032fae886b16356928
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < 05e4a0fa248240efd99a539853e844f0f0a9e6a505e4a0fa248240efd99a539853e844f0f0a9e6a5
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < 1407be30fc17eff918a98e0a990c0e988f11dc841407be30fc17eff918a98e0a990c0e988f11dc84
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < e809a84c802377ef61525a298a1ec1728759b913e809a84c802377ef61525a298a1ec1728759b913
linuxlinux>= 6ba84574026792ce33a40c7da721dea36d0f3973 < 9ab0faa7f9ffe31296dbb9bbe6f76c72c14eea189ab0faa7f9ffe31296dbb9bbe6f76c72c14eea18
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.226-15.10.226-1
linuxlinux_kernel>= 0 < 6.1.106-16.1.106-1
linuxlinux_kernel>= 0 < 6.10.6-16.10.6-1
linuxlinux_kernel>= 0 < 6.10.6-16.10.6-1
linuxlinux_kernel>= 0 < 5.4.0-200.2205.4.0-200.220
linuxlinux_kernel>= 0 < 5.15.0-125.1355.15.0-125.135
linuxlinux_kernel>= 0 < 6.8.0-50.516.8.0-50.51
linuxlinux_kernel>= 5.0 < 5.4.2825.4.282
linuxlinux_kernel>= 5.11 < 5.15.1655.15.165
linuxlinux_kernel>= 5.16 < 6.1.1056.1.105
linuxlinux_kernel>= 5.5 < 5.10.2245.10.224
linuxlinux_kernel>= 6.2 < 6.6.466.6.46
linuxlinux_kernel>= 6.7 < 6.10.56.10.5
msrccbl2_kernel_5.15.164.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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