James Chapman d587d82542 l2tp: make session IDR and tunnel session list coherent ... Modify l2tp_session_register and l2tp_session_unhash so that the session IDR and tunnel session lists remain coherent. To do so, hold the session IDR lock and the tunnel's session list lock when making any changes to either list. Without this change, a rare race condition could hit the WARN_ON_ONCE in l2tp_session_unhash if a thread replaced the IDR entry while another thread was registering the same ID. [ 7126.151795][T17511] WARNING: CPU: 3 PID: 17511 at net/l2tp/l2tp_core.c:1282 l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.163754][T17511] ? show_regs+0x93/0xa0 [ 7126.164157][T17511] ? __warn+0xe5/0x3c0 [ 7126.164536][T17511] ? l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.165070][T17511] ? report_bug+0x2e1/0x500 [ 7126.165486][T17511] ? l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.166013][T17511] ? handle_bug+0x99/0x130 [ 7126.166428][T17511] ? exc_invalid_op+0x35/0x80 [ 7126.166890][T17511] ? asm_exc_invalid_op+0x1a/0x20 [ 7126.167372][T17511] ? l2tp_session_delete.part.0+0x87d/0xbc0 [ 7126.167900][T17511] ? l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.168429][T17511] ? __local_bh_enable_ip+0xa4/0x120 [ 7126.168917][T17511] l2tp_session_delete+0x40/0x50 [ 7126.169369][T17511] pppol2tp_release+0x1a1/0x3f0 [ 7126.169817][T17511] __sock_release+0xb3/0x270 [ 7126.170247][T17511] ? __pfx_sock_close+0x10/0x10 [ 7126.170697][T17511] sock_close+0x1c/0x30 [ 7126.171087][T17511] __fput+0x40b/0xb90 [ 7126.171470][T17511] task_work_run+0x16c/0x260 [ 7126.171897][T17511] ? __pfx_task_work_run+0x10/0x10 [ 7126.172362][T17511] ? srso_alias_return_thunk+0x5/0xfbef5 [ 7126.172863][T17511] ? do_raw_spin_unlock+0x174/0x230 [ 7126.173348][T17511] do_exit+0xaae/0x2b40 [ 7126.173730][T17511] ? srso_alias_return_thunk+0x5/0xfbef5 [ 7126.174235][T17511] ? __pfx_lock_release+0x10/0x10 [ 7126.174690][T17511] ? srso_alias_return_thunk+0x5/0xfbef5 [ 7126.175190][T17511] ? do_raw_spin_lock+0x12c/0x2b0 [ 7126.175650][T17511] ? __pfx_do_exit+0x10/0x10 [ 7126.176072][T17511] ? _raw_spin_unlock_irq+0x23/0x50 [ 7126.176543][T17511] do_group_exit+0xd3/0x2a0 [ 7126.176990][T17511] __x64_sys_exit_group+0x3e/0x50 [ 7126.177456][T17511] x64_sys_call+0x1821/0x1830 [ 7126.177895][T17511] do_syscall_64+0xcb/0x250 [ 7126.178317][T17511] entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: aa5e17e1f5 ("l2tp: store l2tpv3 sessions in per-net IDR") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240718134348.289865-1-jchapman@katalix.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>		2024-07-23 11:24:46 +02:00
..
Kconfig	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
l2tp_core.c	l2tp: make session IDR and tunnel session list coherent	2024-07-23 11:24:46 +02:00
l2tp_core.h	l2tp: replace hlist with simple list for per-tunnel session list	2024-06-21 11:33:34 +01:00
l2tp_debugfs.c	l2tp: replace hlist with simple list for per-tunnel session list	2024-06-21 11:33:34 +01:00
l2tp_eth.c	net l2tp: drop flow hash on forward	2024-04-26 13:48:24 +02:00
l2tp_ip6.c	l2tp: store l2tpv3 sessions in per-net IDR	2024-06-21 11:33:33 +01:00
l2tp_ip.c	l2tp: store l2tpv3 sessions in per-net IDR	2024-06-21 11:33:33 +01:00
l2tp_netlink.c	l2tp: use IDR for all session lookups	2024-06-21 11:33:34 +01:00
l2tp_ppp.c	l2tp: use IDR for all session lookups	2024-06-21 11:33:34 +01:00
Makefile	l2tp: add tracepoint infrastructure to core	2020-08-22 12:44:37 -07:00
trace.h	l2tp: add tracepoint definitions in trace.h	2020-08-22 12:44:37 -07:00