2 Commits

Author	SHA1	Message	Date
David Lebrun	fa79581ea6	ipv6: sr: fix several BUGs when preemption is enabled ... When CONFIG_PREEMPT=y, CONFIG_IPV6=m and CONFIG_SEG6_HMAC=y, seg6_hmac_init() is called during the initialization of the ipv6 module. This causes a subsequent call to smp_processor_id() with preemption enabled, resulting in the following trace. [ 20.451460] BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1 [ 20.452556] caller is debug_smp_processor_id+0x17/0x19 [ 20.453304] CPU: 0 PID: 1 Comm: systemd Not tainted 4.9.0-rc5-00973-g46738b1 #1 [ 20.454406] ffffc9000062fc18 ffffffff813607b2 0000000000000000 ffffffff81a7f782 [ 20.455528] ffffc9000062fc48 ffffffff813778dc 0000000000000000 00000000001dcf98 [ 20.456539] ffffffffa003bd08 ffffffff81af93e0 ffffc9000062fc58 ffffffff81377905 [ 20.456539] Call Trace: [ 20.456539] [<ffffffff813607b2>] dump_stack+0x63/0x7f [ 20.456539] [<ffffffff813778dc>] check_preemption_disabled+0xd1/0xe3 [ 20.456539] [<ffffffff81377905>] debug_smp_processor_id+0x17/0x19 [ 20.460260] [<ffffffffa0061f3b>] seg6_hmac_init+0xfa/0x192 [ipv6] [ 20.460260] [<ffffffffa0061ccc>] seg6_init+0x39/0x6f [ipv6] [ 20.460260] [<ffffffffa006121a>] inet6_init+0x21a/0x321 [ipv6] [ 20.460260] [<ffffffffa0061000>] ? 0xffffffffa0061000 [ 20.460260] [<ffffffff81000457>] do_one_initcall+0x8b/0x115 [ 20.460260] [<ffffffff811328a3>] do_init_module+0x53/0x1c4 [ 20.460260] [<ffffffff8110650a>] load_module+0x1153/0x14ec [ 20.460260] [<ffffffff81106a7b>] SYSC_finit_module+0x8c/0xb9 [ 20.460260] [<ffffffff81106a7b>] ? SYSC_finit_module+0x8c/0xb9 [ 20.460260] [<ffffffff81106abc>] SyS_finit_module+0x9/0xb [ 20.460260] [<ffffffff810014d1>] do_syscall_64+0x62/0x75 [ 20.460260] [<ffffffff816834f0>] entry_SYSCALL64_slow_path+0x25/0x25 Moreover, dst_cache_* functions also call smp_processor_id(), generating a similar trace. This patch uses raw_cpu_ptr() in seg6_hmac_init() rather than this_cpu_ptr() and disable preemption when using dst_cache_* functions. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>	2017-01-13 12:29:55 -05:00
David Lebrun	bf355b8d2c	ipv6: sr: add core files for SR HMAC support ... This patch adds the necessary functions to compute and check the HMAC signature of an SR-enabled packet. Two HMAC algorithms are supported: hmac(sha1) and hmac(sha256). In order to avoid dynamic memory allocation for each HMAC computation, a per-cpu ring buffer is allocated for this purpose. A new per-interface sysctl called seg6_require_hmac is added, allowing a user-defined policy for processing HMAC-signed SR-enabled packets. A value of -1 means that the HMAC field will always be ignored. A value of 0 means that if an HMAC field is present, its validity will be enforced (the packet is dropped is the signature is incorrect). Finally, a value of 1 means that any SR-enabled packet that does not contain an HMAC signature or whose signature is incorrect will be dropped. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>	2016-11-09 20:40:06 -05:00