{"id":"DEBIAN-CVE-2022-49142","details":"In the Linux kernel, the following vulnerability has been resolved:  net: preserve skb_end_offset() in skb_unclone_keeptruesize()  syzbot found another way to trigger the infamous WARN_ON_ONCE(delta \u003c len) in skb_try_coalesce() [1]  I was able to root cause the issue to kfence.  When kfence is in action, the following assertion is no longer true:  int size = xxxx; void *ptr1 = kmalloc(size, gfp); void *ptr2 = kmalloc(size, gfp);  if (ptr1 && ptr2) \tASSERT(ksize(ptr1) == ksize(ptr2));  We attempted to fix these issues in the blamed commits, but forgot that TCP was possibly shifting data after skb_unclone_keeptruesize() has been used, notably from tcp_retrans_try_collapse().  So we not only need to keep same skb-\u003etruesize value, we also need to make sure TCP wont fill new tailroom that pskb_expand_head() was able to get from a addr = kmalloc(...) followed by ksize(addr)  Split skb_unclone_keeptruesize() into two parts:  1) Inline skb_unclone_keeptruesize() for the common case,    when skb is not cloned.  2) Out of line __skb_unclone_keeptruesize() for the 'slow path'.  WARNING: CPU: 1 PID: 6490 at net/core/skbuff.c:5295 skb_try_coalesce+0x1235/0x1560 net/core/skbuff.c:5295 Modules linked in: CPU: 1 PID: 6490 Comm: syz-executor161 Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_try_coalesce+0x1235/0x1560 net/core/skbuff.c:5295 Code: bf 01 00 00 00 0f b7 c0 89 c6 89 44 24 20 e8 62 24 4e fa 8b 44 24 20 83 e8 01 0f 85 e5 f0 ff ff e9 87 f4 ff ff e8 cb 20 4e fa \u003c0f\u003e 0b e9 06 f9 ff ff e8 af b2 95 fa e9 69 f0 ff ff e8 95 b2 95 fa RSP: 0018:ffffc900063af268 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 00000000ffffffd5 RCX: 0000000000000000 RDX: ffff88806fc05700 RSI: ffffffff872abd55 RDI: 0000000000000003 RBP: ffff88806e675500 R08: 00000000ffffffd5 R09: 0000000000000000 R10: ffffffff872ab659 R11: 0000000000000000 R12: ffff88806dd554e8 R13: ffff88806dd9bac0 R14: ffff88806dd9a2c0 R15: 0000000000000155 FS:  00007f18014f9700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002000 CR3: 000000006be7a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace:  \u003cTASK\u003e  tcp_try_coalesce net/ipv4/tcp_input.c:4651 [inline]  tcp_try_coalesce+0x393/0x920 net/ipv4/tcp_input.c:4630  tcp_queue_rcv+0x8a/0x6e0 net/ipv4/tcp_input.c:4914  tcp_data_queue+0x11fd/0x4bb0 net/ipv4/tcp_input.c:5025  tcp_rcv_established+0x81e/0x1ff0 net/ipv4/tcp_input.c:5947  tcp_v4_do_rcv+0x65e/0x980 net/ipv4/tcp_ipv4.c:1719  sk_backlog_rcv include/net/sock.h:1037 [inline]  __release_sock+0x134/0x3b0 net/core/sock.c:2779  release_sock+0x54/0x1b0 net/core/sock.c:3311  sk_wait_data+0x177/0x450 net/core/sock.c:2821  tcp_recvmsg_locked+0xe28/0x1fd0 net/ipv4/tcp.c:2457  tcp_recvmsg+0x137/0x610 net/ipv4/tcp.c:2572  inet_recvmsg+0x11b/0x5e0 net/ipv4/af_inet.c:850  sock_recvmsg_nosec net/socket.c:948 [inline]  sock_recvmsg net/socket.c:966 [inline]  sock_recvmsg net/socket.c:962 [inline]  ____sys_recvmsg+0x2c4/0x600 net/socket.c:2632  ___sys_recvmsg+0x127/0x200 net/socket.c:2674  __sys_recvmsg+0xe2/0x1a0 net/socket.c:2704  do_syscall_x64 arch/x86/entry/common.c:50 [inline]  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80  entry_SYSCALL_64_after_hwframe+0x44/0xae","modified":"2026-09-01T16:05:30.040281114Z","published":"2025-02-26T07:00:51.420Z","upstream":["CVE-2022-49142"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-49142"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49142.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49142.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49142.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}