{"id":"DEBIAN-CVE-2022-49372","details":"In the Linux kernel, the following vulnerability has been resolved:  tcp: tcp_rtx_synack() can be called from process context  Laurent reported the enclosed report [1]  This bug triggers with following coditions:  0) Kernel built with CONFIG_DEBUG_PREEMPT=y  1) A new passive FastOpen TCP socket is created.    This FO socket waits for an ACK coming from client to be a complete    ESTABLISHED one. 2) A socket operation on this socket goes through lock_sock()    release_sock() dance. 3) While the socket is owned by the user in step 2),    a retransmit of the SYN is received and stored in socket backlog. 4) At release_sock() time, the socket backlog is processed while    in process context. 5) A SYNACK packet is cooked in response of the SYN retransmit. 6) -\u003e tcp_rtx_synack() is called in process context.  Before blamed commit, tcp_rtx_synack() was always called from BH handler, from a timer handler.  Fix this by using TCP_INC_STATS() & NET_INC_STATS() which do not assume caller is in non preemptible context.  [1] BUG: using __this_cpu_add() in preemptible [00000000] code: epollpep/2180 caller is tcp_rtx_synack.part.0+0x36/0xc0 CPU: 10 PID: 2180 Comm: epollpep Tainted: G           OE     5.16.0-0.bpo.4-amd64 #1  Debian 5.16.12-1~bpo11+1 Hardware name: Supermicro SYS-5039MC-H8TRF/X11SCD-F, BIOS 1.7 11/23/2021 Call Trace:  \u003cTASK\u003e  dump_stack_lvl+0x48/0x5e  check_preemption_disabled+0xde/0xe0  tcp_rtx_synack.part.0+0x36/0xc0  tcp_rtx_synack+0x8d/0xa0  ? kmem_cache_alloc+0x2e0/0x3e0  ? apparmor_file_alloc_security+0x3b/0x1f0  inet_rtx_syn_ack+0x16/0x30  tcp_check_req+0x367/0x610  tcp_rcv_state_process+0x91/0xf60  ? get_nohz_timer_target+0x18/0x1a0  ? lock_timer_base+0x61/0x80  ? preempt_count_add+0x68/0xa0  tcp_v4_do_rcv+0xbd/0x270  __release_sock+0x6d/0xb0  release_sock+0x2b/0x90  sock_setsockopt+0x138/0x1140  ? __sys_getsockname+0x7e/0xc0  ? aa_sk_perm+0x3e/0x1a0  __sys_setsockopt+0x198/0x1e0  __x64_sys_setsockopt+0x21/0x30  do_syscall_64+0x38/0xc0  entry_SYSCALL_64_after_hwframe+0x44/0xae","modified":"2026-09-01T16:01:00.837095070Z","published":"2025-02-26T07:01:13.870Z","upstream":["CVE-2022-49372"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-49372"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.18.5-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49372.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.18.5-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49372.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.18.5-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49372.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"}]}