2 Commits

Author	SHA1	Message	Date
Peter Zijlstra	4382159696	cfi: Flip headers ... Normal include order is that linux/foo.h should include asm/foo.h, CFI has it the wrong way around. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20231215092707.231038174@infradead.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2023-12-15 16:25:55 -08:00
Sami Tolvanen	3c516f89e1	x86: Add support for CONFIG_CFI_CLANG ... With CONFIG_CFI_CLANG, the compiler injects a type preamble immediately before each function and a check to validate the target function type before indirect calls: ; type preamble __cfi_function: mov <id>, %eax function: ... ; indirect call check mov -<id>,%r10d add -0x4(%r11),%r10d je .Ltmp1 ud2 .Ltmp1: call __x86_indirect_thunk_r11 Add error handling code for the ud2 traps emitted for the checks, and allow CONFIG_CFI_CLANG to be selected on x86_64. This produces the following oops on CFI failure (generated using lkdtm): [ 21.441706] CFI failure at lkdtm_indirect_call+0x16/0x20 [lkdtm] (target: lkdtm_increment_int+0x0/0x10 [lkdtm]; expected type: 0x7e0c52a) [ 21.444579] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 21.445296] CPU: 0 PID: 132 Comm: sh Not tainted 5.19.0-rc8-00020-g9f27360e674c #1 [ 21.445296] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 21.445296] RIP: 0010:lkdtm_indirect_call+0x16/0x20 [lkdtm] [ 21.445296] Code: 52 1c c0 48 c7 c1 c5 50 1c c0 e9 25 48 2a cc 0f 1f 44 00 00 49 89 fb 48 c7 c7 50 b4 1c c0 41 ba 5b ad f3 81 45 03 53 f8 [ 21.445296] RSP: 0018:ffffa9f9c02ffdc0 EFLAGS: 00000292 [ 21.445296] RAX: 0000000000000027 RBX: ffffffffc01cb300 RCX: 385cbbd2e070a700 [ 21.445296] RDX: 0000000000000000 RSI: c0000000ffffdfff RDI: ffffffffc01cb450 [ 21.445296] RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffff8d081610 [ 21.445296] R10: 00000000bcc90825 R11: ffffffffc01c2fc0 R12: 0000000000000000 [ 21.445296] R13: ffffa31b827a6000 R14: 0000000000000000 R15: 0000000000000002 [ 21.445296] FS: 00007f08b42216a0(0000) GS:ffffa31b9f400000(0000) knlGS:0000000000000000 [ 21.445296] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 21.445296] CR2: 0000000000c76678 CR3: 0000000001940000 CR4: 00000000000006f0 [ 21.445296] Call Trace: [ 21.445296] <TASK> [ 21.445296] lkdtm_CFI_FORWARD_PROTO+0x30/0x50 [lkdtm] [ 21.445296] direct_entry+0x12d/0x140 [lkdtm] [ 21.445296] full_proxy_write+0x5d/0xb0 [ 21.445296] vfs_write+0x144/0x460 [ 21.445296] ? __x64_sys_wait4+0x5a/0xc0 [ 21.445296] ksys_write+0x69/0xd0 [ 21.445296] do_syscall_64+0x51/0xa0 [ 21.445296] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 21.445296] RIP: 0033:0x7f08b41a6fe1 [ 21.445296] Code: be 07 00 00 00 41 89 c0 e8 7e ff ff ff 44 89 c7 89 04 24 e8 91 c6 02 00 8b 04 24 48 83 c4 68 c3 48 63 ff b8 01 00 00 03 [ 21.445296] RSP: 002b:00007ffcdf65c2e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 21.445296] RAX: ffffffffffffffda RBX: 00007f08b4221690 RCX: 00007f08b41a6fe1 [ 21.445296] RDX: 0000000000000012 RSI: 0000000000c738f0 RDI: 0000000000000001 [ 21.445296] RBP: 0000000000000001 R08: fefefefefefefeff R09: fefefefeffc5ff4e [ 21.445296] R10: 00007f08b42222b0 R11: 0000000000000246 R12: 0000000000c738f0 [ 21.445296] R13: 0000000000000012 R14: 00007ffcdf65c401 R15: 0000000000c70450 [ 21.445296] </TASK> [ 21.445296] Modules linked in: lkdtm [ 21.445296] Dumping ftrace buffer: [ 21.445296] (ftrace buffer empty) [ 21.471442] ---[ end trace 0000000000000000 ]--- [ 21.471811] RIP: 0010:lkdtm_indirect_call+0x16/0x20 [lkdtm] [ 21.472467] Code: 52 1c c0 48 c7 c1 c5 50 1c c0 e9 25 48 2a cc 0f 1f 44 00 00 49 89 fb 48 c7 c7 50 b4 1c c0 41 ba 5b ad f3 81 45 03 53 f8 [ 21.474400] RSP: 0018:ffffa9f9c02ffdc0 EFLAGS: 00000292 [ 21.474735] RAX: 0000000000000027 RBX: ffffffffc01cb300 RCX: 385cbbd2e070a700 [ 21.475664] RDX: 0000000000000000 RSI: c0000000ffffdfff RDI: ffffffffc01cb450 [ 21.476471] RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffff8d081610 [ 21.477127] R10: 00000000bcc90825 R11: ffffffffc01c2fc0 R12: 0000000000000000 [ 21.477959] R13: ffffa31b827a6000 R14: 0000000000000000 R15: 0000000000000002 [ 21.478657] FS: 00007f08b42216a0(0000) GS:ffffa31b9f400000(0000) knlGS:0000000000000000 [ 21.479577] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 21.480307] CR2: 0000000000c76678 CR3: 0000000001940000 CR4: 00000000000006f0 [ 21.481460] Kernel panic - not syncing: Fatal exception Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-23-samitolvanen@google.com	2022-09-26 10:13:16 -07:00