{"id":"DEBIAN-CVE-2022-49979","details":"In the Linux kernel, the following vulnerability has been resolved:  net: fix refcount bug in sk_psock_get (2)  Syzkaller reports refcount bug as follows: ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 1 PID: 3605 at lib/refcount.c:19 refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19 Modules linked in: CPU: 1 PID: 3605 Comm: syz-executor208 Not tainted 5.18.0-syzkaller-03023-g7e062cda7d90 #0  \u003cTASK\u003e  __refcount_add_not_zero include/linux/refcount.h:163 [inline]  __refcount_inc_not_zero include/linux/refcount.h:227 [inline]  refcount_inc_not_zero include/linux/refcount.h:245 [inline]  sk_psock_get+0x3bc/0x410 include/linux/skmsg.h:439  tls_data_ready+0x6d/0x1b0 net/tls/tls_sw.c:2091  tcp_data_ready+0x106/0x520 net/ipv4/tcp_input.c:4983  tcp_data_queue+0x25f2/0x4c90 net/ipv4/tcp_input.c:5057  tcp_rcv_state_process+0x1774/0x4e80 net/ipv4/tcp_input.c:6659  tcp_v4_do_rcv+0x339/0x980 net/ipv4/tcp_ipv4.c:1682  sk_backlog_rcv include/net/sock.h:1061 [inline]  __release_sock+0x134/0x3b0 net/core/sock.c:2849  release_sock+0x54/0x1b0 net/core/sock.c:3404  inet_shutdown+0x1e0/0x430 net/ipv4/af_inet.c:909  __sys_shutdown_sock net/socket.c:2331 [inline]  __sys_shutdown_sock net/socket.c:2325 [inline]  __sys_shutdown+0xf1/0x1b0 net/socket.c:2343  __do_sys_shutdown net/socket.c:2351 [inline]  __se_sys_shutdown net/socket.c:2349 [inline]  __x64_sys_shutdown+0x50/0x70 net/socket.c:2349  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+0x46/0xb0  \u003c/TASK\u003e  During SMC fallback process in connect syscall, kernel will replaces TCP with SMC. In order to forward wakeup smc socket waitqueue after fallback, kernel will sets clcsk-\u003esk_user_data to origin smc socket in smc_fback_replace_callbacks().  Later, in shutdown syscall, kernel will calls sk_psock_get(), which treats the clcsk-\u003esk_user_data as psock type, triggering the refcnt warning.  So, the root cause is that smc and psock, both will use sk_user_data field. So they will mismatch this field easily.  This patch solves it by using another bit(defined as SK_USER_DATA_PSOCK) in PTRMASK, to mark whether sk_user_data points to a psock object or not. This patch depends on a PTRMASK introduced in commit f1ff5ce2cd5e (\"net, sk_msg: Clear sk_user_data pointer on clone if tagged\").  For there will possibly be more flags in the sk_user_data field, this patch also refactor sk_user_data flags code to be more generic to improve its maintainability.","modified":"2026-09-01T16:05:33.848588387Z","published":"2025-06-18T11:15:25.363Z","upstream":["CVE-2022-49979"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-49979"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49979.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49979.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49979.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"}]}