WSL2-Linux-Kernel/arch
Jinghao Jia 1d5c1617e1 x86/kprobes: fix incorrect return address calculation in kprobe_emulate_call_indirect
commit f5d03da48d062966c94f0199d20be0b3a37a7982 upstream.

kprobe_emulate_call_indirect currently uses int3_emulate_call to emulate
indirect calls. However, int3_emulate_call always assumes the size of
the call to be 5 bytes when calculating the return address. This is
incorrect for register-based indirect calls in x86, which can be either
2 or 3 bytes depending on whether REX prefix is used. At kprobe runtime,
the incorrect return address causes control flow to land onto the wrong
place after return -- possibly not a valid instruction boundary. This
can lead to a panic like the following:

[    7.308204][    C1] BUG: unable to handle page fault for address: 000000000002b4d8
[    7.308883][    C1] #PF: supervisor read access in kernel mode
[    7.309168][    C1] #PF: error_code(0x0000) - not-present page
[    7.309461][    C1] PGD 0 P4D 0
[    7.309652][    C1] Oops: 0000 [#1] SMP
[    7.309929][    C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.7.0-rc5-trace-for-next #6
[    7.310397][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014
[    7.311068][    C1] RIP: 0010:__common_interrupt+0x52/0xc0
[    7.311349][    C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[    7.312512][    C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[    7.312899][    C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[    7.313334][    C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[    7.313702][    C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[    7.314146][    C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[    7.314509][    C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[    7.314951][    C1] FS:  0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[    7.315396][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.315691][    C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[    7.316153][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.316508][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.316948][    C1] Call Trace:
[    7.317123][    C1]  <IRQ>
[    7.317279][    C1]  ? __die_body+0x64/0xb0
[    7.317482][    C1]  ? page_fault_oops+0x248/0x370
[    7.317712][    C1]  ? __wake_up+0x96/0xb0
[    7.317964][    C1]  ? exc_page_fault+0x62/0x130
[    7.318211][    C1]  ? asm_exc_page_fault+0x22/0x30
[    7.318444][    C1]  ? __cfi_native_send_call_func_single_ipi+0x10/0x10
[    7.318860][    C1]  ? default_idle+0xb/0x10
[    7.319063][    C1]  ? __common_interrupt+0x52/0xc0
[    7.319330][    C1]  common_interrupt+0x78/0x90
[    7.319546][    C1]  </IRQ>
[    7.319679][    C1]  <TASK>
[    7.319854][    C1]  asm_common_interrupt+0x22/0x40
[    7.320082][    C1] RIP: 0010:default_idle+0xb/0x10
[    7.320309][    C1] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 66 90 0f 00 2d 09 b9 3b 00 fb f4 <fa> c3 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 e9
[    7.321449][    C1] RSP: 0018:ffffc9000009bee8 EFLAGS: 00000256
[    7.321808][    C1] RAX: ffff88813bca8b68 RBX: 0000000000000001 RCX: 000000000001ef0c
[    7.322227][    C1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000001ef0c
[    7.322656][    C1] RBP: ffffc9000009bef8 R08: 8000000000000000 R09: 00000000000008c2
[    7.323083][    C1] R10: 0000000000000000 R11: ffffffff81058e70 R12: 0000000000000000
[    7.323530][    C1] R13: ffff8881002b30c0 R14: 0000000000000000 R15: 0000000000000000
[    7.323948][    C1]  ? __cfi_lapic_next_deadline+0x10/0x10
[    7.324239][    C1]  default_idle_call+0x31/0x50
[    7.324464][    C1]  do_idle+0xd3/0x240
[    7.324690][    C1]  cpu_startup_entry+0x25/0x30
[    7.324983][    C1]  start_secondary+0xb4/0xc0
[    7.325217][    C1]  secondary_startup_64_no_verify+0x179/0x17b
[    7.325498][    C1]  </TASK>
[    7.325641][    C1] Modules linked in:
[    7.325906][    C1] CR2: 000000000002b4d8
[    7.326104][    C1] ---[ end trace 0000000000000000 ]---
[    7.326354][    C1] RIP: 0010:__common_interrupt+0x52/0xc0
[    7.326614][    C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[    7.327570][    C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[    7.327910][    C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[    7.328273][    C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[    7.328632][    C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[    7.329223][    C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[    7.329780][    C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[    7.330193][    C1] FS:  0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[    7.330632][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.331050][    C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[    7.331454][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    7.331854][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    7.332236][    C1] Kernel panic - not syncing: Fatal exception in interrupt
[    7.332730][    C1] Kernel Offset: disabled
[    7.333044][    C1] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

The relevant assembly code is (from objdump, faulting address
highlighted):

ffffffff8102ed9d:       41 ff d3                  call   *%r11
ffffffff8102eda0:       65 48 <8b> 05 30 c7 ff    mov    %gs:0x7effc730(%rip),%rax

The emulation incorrectly sets the return address to be ffffffff8102ed9d
+ 0x5 = ffffffff8102eda2, which is the 8b byte in the middle of the next
mov. This in turn causes incorrect subsequent instruction decoding and
eventually triggers the page fault above.

Instead of invoking int3_emulate_call, perform push and jmp emulation
directly in kprobe_emulate_call_indirect. At this point we can obtain
the instruction size from p->ainsn.size so that we can calculate the
correct return address.

Link: https://lore.kernel.org/all/20240102233345.385475-1-jinghao7@illinois.edu/

Fixes: 6256e668b7 ("x86/kprobes: Use int3 instead of debug trap for single-step")
Cc: stable@vger.kernel.org
Signed-off-by: Jinghao Jia <jinghao7@illinois.edu>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-15 18:51:22 +01:00
..
alpha alpha: remove __init annotation from exported page_is_ram() 2023-08-16 18:22:03 +02:00
arc memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
arm ARM: sun9i: smp: Fix array-index-out-of-bounds read in sunxi_mc_smp_init 2024-01-15 18:51:14 +01:00
arm64 KVM: arm64: vgic: Force vcpu vgic teardown on vcpu destroy 2024-01-05 15:13:35 +01:00
csky kprobes: treewide: Cleanup the error messages for kprobes 2023-02-22 12:57:00 +01:00
h8300 h8300: Fix build errors from do_exit() to make_task_dead() transition 2023-02-01 08:27:21 +01:00
hexagon hexagon: Fix function name in die() 2023-02-01 08:27:20 +01:00
ia64 memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
m68k memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
microblaze exit: Add and use make_task_dead. 2023-02-01 08:27:20 +01:00
mips MIPS: Loongson64: Handle more memory types passed from firmware 2023-12-20 15:17:33 +01:00
nds32 exit: Add and use make_task_dead. 2023-02-01 08:27:20 +01:00
nios2 nios2: dts: Fix tse_mac "max-frame-size" property 2023-06-21 15:59:14 +02:00
openrisc openrisc: Properly store r31 to pt_regs on unhandled exceptions 2023-05-11 23:00:37 +09:00
parisc parisc: Drop the HP-UX ENOSYM and EREMOTERELEASE error codes 2023-12-08 08:48:02 +01:00
powerpc powerpc/ftrace: Fix stack teardown in ftrace_no_trace 2023-12-20 15:17:43 +01:00
riscv riscv: fix misaligned access handling of C.SWSP and C.SDSP 2023-12-13 18:36:41 +01:00
s390 s390/vx: fix save/restore of fpu kernel context 2024-01-05 15:13:28 +01:00
sh sh: bios: Revive earlyprintk support 2023-11-20 11:08:23 +01:00
sparc sparc32: fix a braino in fault handling in csum_and_copy_..._user() 2023-11-08 17:26:42 +01:00
um um: Fix hostaudio build errors 2023-09-19 12:22:49 +02:00
x86 x86/kprobes: fix incorrect return address calculation in kprobe_emulate_call_indirect 2024-01-15 18:51:22 +01:00
xtensa xtensa: boot/lib: fix function prototypes 2023-10-06 13:18:14 +02:00
.gitignore
Kconfig init: Provide arch_cpu_finalize_init() 2023-08-08 19:58:30 +02:00