CVSS: -EPSS: 0%CPEs: 10EXPL: 0CVE-2024-49949 – net: avoid potential underflow in qdisc_pkt_len_init() with UFO
https://notcve.org/view.php?id=CVE-2024-49949
In the Linux kernel, the following vulnerability has been resolved: net: avoid potential underflow in qdisc_pkt_len_init() with UFO After commit 7c6d2ecbda83 ("net: be more gentle about silly gso requests coming from user") virtio_net_hdr_to_skb() had sanity check to detect malicious attempts from user space to cook a bad GSO packet. Then commit cf9acc90c80ec ("net: virtio_net_hdr_to_skb: count transport header in UFO") while fixing one issue, allowed user space to cook a GSO packet with the following characteristic : IPv4 SKB_GSO_UDP, gso_size=3, skb->len = 28. When this packet arrives in qdisc_pkt_len_init(), we end up with hdr_len = 28 (IPv4 header + UDP header), matching skb->len Then the following sets gso_segs to 0 : gso_segs = DIV_ROUND_UP(skb->len - hdr_len, shinfo->gso_size); Then later we set qdisc_skb_cb(skb)->pkt_len to back to zero :/ qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; This leads to the following crash in fq_codel [1] qdisc_pkt_len_init() is best effort, we only want an estimation of the bytes sent on the wire, not crashing the kernel. This patch is fixing this particular issue, a following one adds more sanity checks for another potential bug. [1] [ 70.724101] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 70.724561] #PF: supervisor read access in kernel mode [ 70.724561] #PF: error_code(0x0000) - not-present page [ 70.724561] PGD 10ac61067 P4D 10ac61067 PUD 107ee2067 PMD 0 [ 70.724561] Oops: Oops: 0000 [#1] SMP NOPTI [ 70.724561] CPU: 11 UID: 0 PID: 2163 Comm: b358537762 Not tainted 6.11.0-virtme #991 [ 70.724561] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 70.724561] RIP: 0010:fq_codel_enqueue (net/sched/sch_fq_codel.c:120 net/sched/sch_fq_codel.c:168 net/sched/sch_fq_codel.c:230) sch_fq_codel [ 70.724561] Code: 24 08 49 c1 e1 06 44 89 7c 24 18 45 31 ed 45 31 c0 31 ff 89 44 24 14 4c 03 8b 90 01 00 00 eb 04 39 ca 73 37 4d 8b 39 83 c7 01 <49> 8b 17 49 89 11 41 8b 57 28 45 8b 5f 34 49 c7 07 00 00 00 00 49 All code ======== 0: 24 08 and $0x8,%al 2: 49 c1 e1 06 shl $0x6,%r9 6: 44 89 7c 24 18 mov %r15d,0x18(%rsp) b: 45 31 ed xor %r13d,%r13d e: 45 31 c0 xor %r8d,%r8d 11: 31 ff xor %edi,%edi 13: 89 44 24 14 mov %eax,0x14(%rsp) 17: 4c 03 8b 90 01 00 00 add 0x190(%rbx),%r9 1e: eb 04 jmp 0x24 20: 39 ca cmp %ecx,%edx 22: 73 37 jae 0x5b 24: 4d 8b 39 mov (%r9),%r15 27: 83 c7 01 add $0x1,%edi 2a:* 49 8b 17 mov (%r15),%rdx <-- trapping instruction 2d: 49 89 11 mov %rdx,(%r9) 30: 41 8b 57 28 mov 0x28(%r15),%edx 34: 45 8b 5f 34 mov 0x34(%r15),%r11d 38: 49 c7 07 00 00 00 00 movq $0x0,(%r15) 3f: 49 rex.WB Code starting with the faulting instruction =========================================== 0: 49 8b 17 mov (%r15),%rdx 3: 49 89 11 mov %rdx,(%r9) 6: 41 8b 57 28 mov 0x28(%r15),%edx a: 45 8b 5f 34 mov 0x34(%r15),%r11d e: 49 c7 07 00 00 00 00 movq $0x0,(%r15) 15: 49 rex.WB [ 70.724561] RSP: 0018:ffff95ae85e6fb90 EFLAGS: 00000202 [ 70.724561] RAX: 0000000002000000 RBX: ffff95ae841de000 RCX: 0000000000000000 [ 70.724561] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 [ 70.724561] RBP: ffff95ae85e6fbf8 R08: 0000000000000000 R09: ffff95b710a30000 [ 70.724561] R10: 0000000000000000 R11: bdf289445ce31881 R12: ffff95ae85e6fc58 [ 70.724561] R13: 0000000000000000 R14: 0000000000000040 R15: 0000000000000000 [ 70.724561] FS: 000000002c5c1380(0000) GS:ffff95bd7fcc0000(0000) knlGS:0000000000000000 [ 70.724561] CS: 0010 DS: 0000 ES: 0000 C ---truncated--- • https://git.kernel.org/stable/c/960b360ca7463921c1a6b72e7066a706d6406223 https://git.kernel.org/stable/c/fb2dbc124a7f800cd0e4f901a1bbb769a017104c https://git.kernel.org/stable/c/8e6bae950da9dc2d2c6c18b1c6b206dc00dc8772 https://git.kernel.org/stable/c/0f810d06b507aa40fef8d1ac0a88e6d0590dbfc3 https://git.kernel.org/stable/c/cf9acc90c80ecbee00334aa85d92f4e74014bcff https://git.kernel.org/stable/c/2128303bff700c857739a0af8cc39c1a41840650 https://git.kernel.org/stable/c/d70ca7598943572d5e384227bd268acb5109bf72 https://git.kernel.org/stable/c/1598d70ad9c7d0a4d9d54b82094e9f459 •
CVSS: -EPSS: 0%CPEs: 9EXPL: 0CVE-2024-49948 – net: add more sanity checks to qdisc_pkt_len_init()
https://notcve.org/view.php?id=CVE-2024-49948
In the Linux kernel, the following vulnerability has been resolved: net: add more sanity checks to qdisc_pkt_len_init() One path takes care of SKB_GSO_DODGY, assuming skb->len is bigger than hdr_len. virtio_net_hdr_to_skb() does not fully dissect TCP headers, it only make sure it is at least 20 bytes. It is possible for an user to provide a malicious 'GSO' packet, total length of 80 bytes. - 20 bytes of IPv4 header - 60 bytes TCP header - a small gso_size like 8 virtio_net_hdr_to_skb() would declare this packet as a normal GSO packet, because it would see 40 bytes of payload, bigger than gso_size. We need to make detect this case to not underflow qdisc_skb_cb(skb)->pkt_len. • https://git.kernel.org/stable/c/1def9238d4aa2146924994aa4b7dc861f03b9362 https://git.kernel.org/stable/c/d7d1a28f5dd57b4d83def876f8d7b4403bd37df9 https://git.kernel.org/stable/c/473426a1d53a68dd1e718e6cd00d57936993fa6c https://git.kernel.org/stable/c/566a931a1436d0e0ad13708ea55479b95426213c https://git.kernel.org/stable/c/2415f465730e48b6e38da1c7c097317bf5dd2d20 https://git.kernel.org/stable/c/27a8fabc54d2f960d47bdfbebf2bdc6e8a92a4c4 https://git.kernel.org/stable/c/9b0ee571d20a238a22722126abdfde61f1b2bdd0 https://git.kernel.org/stable/c/ff1c3cadcf405ab37dd91418a62a7acec •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-49945 – net/ncsi: Disable the ncsi work before freeing the associated structure
https://notcve.org/view.php?id=CVE-2024-49945
In the Linux kernel, the following vulnerability has been resolved: net/ncsi: Disable the ncsi work before freeing the associated structure The work function can run after the ncsi device is freed, resulting in use-after-free bugs or kernel panic. • https://git.kernel.org/stable/c/2d283bdd079c0ad4da020bbc9e9c2a4280823098 https://git.kernel.org/stable/c/f6ca58696749268181f43150b3553f2bafd71e42 https://git.kernel.org/stable/c/dd41dab62f32d9e9e0669af8459d12a93834b238 https://git.kernel.org/stable/c/a0ffa68c70b367358b2672cdab6fa5bc4c40de2c •
CVSS: -EPSS: 0%CPEs: 9EXPL: 0CVE-2024-49944 – sctp: set sk_state back to CLOSED if autobind fails in sctp_listen_start
https://notcve.org/view.php?id=CVE-2024-49944
In the Linux kernel, the following vulnerability has been resolved: sctp: set sk_state back to CLOSED if autobind fails in sctp_listen_start In sctp_listen_start() invoked by sctp_inet_listen(), it should set the sk_state back to CLOSED if sctp_autobind() fails due to whatever reason. Otherwise, next time when calling sctp_inet_listen(), if sctp_sk(sk)->reuse is already set via setsockopt(SCTP_REUSE_PORT), sctp_sk(sk)->bind_hash will be dereferenced as sk_state is LISTENING, which causes a crash as bind_hash is NULL. KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:sctp_inet_listen+0x7f0/0xa20 net/sctp/socket.c:8617 Call Trace: <TASK> __sys_listen_socket net/socket.c:1883 [inline] __sys_listen+0x1b7/0x230 net/socket.c:1894 __do_sys_listen net/socket.c:1902 [inline] • https://git.kernel.org/stable/c/5e8f3f703ae4e4af65e2695e486b3cd198328863 https://git.kernel.org/stable/c/89bbead9d897c77d0b566349c8643030ff2abeba https://git.kernel.org/stable/c/0e4e2e60556c6ed00e8450b720f106a268d23062 https://git.kernel.org/stable/c/dd70c8a89ef99c3d53127fe19e51ef47c3f860fa https://git.kernel.org/stable/c/e7a8442195e8ebd97df467ce4742980ab57edcce https://git.kernel.org/stable/c/9230a59eda0878d7ecaa901d876aec76f57bd455 https://git.kernel.org/stable/c/7f64cb5b4d8c872296eda0fdce3bcf099eec7aa7 https://git.kernel.org/stable/c/f032e1dac30b3376c7d6026fb01a8c403 •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2024-49940 – l2tp: prevent possible tunnel refcount underflow
https://notcve.org/view.php?id=CVE-2024-49940
In the Linux kernel, the following vulnerability has been resolved: l2tp: prevent possible tunnel refcount underflow When a session is created, it sets a backpointer to its tunnel. When the session refcount drops to 0, l2tp_session_free drops the tunnel refcount if session->tunnel is non-NULL. However, session->tunnel is set in l2tp_session_create, before the tunnel refcount is incremented by l2tp_session_register, which leaves a small window where session->tunnel is non-NULL when the tunnel refcount hasn't been bumped. Moving the assignment to l2tp_session_register is trivial but l2tp_session_create calls l2tp_session_set_header_len which uses session->tunnel to get the tunnel's encap. Add an encap arg to l2tp_session_set_header_len to avoid using session->tunnel. If l2tpv3 sessions have colliding IDs, it is possible for l2tp_v3_session_get to race with l2tp_session_register and fetch a session which doesn't yet have session->tunnel set. Add a check for this case. • https://git.kernel.org/stable/c/f7415e60c25a6108cd7955a20b2e66b6251ffe02 https://git.kernel.org/stable/c/24256415d18695b46da06c93135f5b51c548b950 •