linux

mirror of https://github.com/raspberrypi/linux.git synced 2025-12-06 18:09:56 +00:00

Files

Alexei Starovoitov 75e3417f89 bpf: Prevent memory disambiguation attack

commit af86ca4e30 upstream

Detect code patterns where malicious 'speculative store bypass' can be used
and sanitize such patterns.

 39: (bf) r3 = r10
 40: (07) r3 += -216
 41: (79) r8 = *(u64 *)(r7 +0)   // slow read
 42: (7a) *(u64 *)(r10 -72) = 0  // verifier inserts this instruction
 43: (7b) *(u64 *)(r8 +0) = r3   // this store becomes slow due to r8
 44: (79) r1 = *(u64 *)(r6 +0)   // cpu speculatively executes this load
 45: (71) r2 = *(u8 *)(r1 +0)    // speculatively arbitrary 'load byte'
                                 // is now sanitized

Above code after x86 JIT becomes:
 e5: mov    %rbp,%rdx
 e8: add    $0xffffffffffffff28,%rdx
 ef: mov    0x0(%r13),%r14
 f3: movq   $0x0,-0x48(%rbp)
 fb: mov    %rdx,0x0(%r14)
 ff: mov    0x0(%rbx),%rdi
103: movzbq 0x0(%rdi),%rsi

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2018-05-22 18:56:31 +02:00

arraymap.c

bpf: add schedule points in percpu arrays management

2018-02-22 21:27:06 +01:00

bpf_lru_list.c

bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4

2017-04-17 13:55:52 -04:00

bpf_lru_list.h

bpf: Only set node->ref = 1 if it has not been set

2017-09-01 09:57:39 -07:00

cgroup.c

bpf/cgroup: fix a verification error for a CGROUP_DEVICE type prog