system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-07-22 11:10:46 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge branch 'Fix offset when fault occurs in strncpy_from_kernel_nofault()'

Browse source 
Alban Crequy says:

====================

Hi,

This is v2 of the fix & selftest previously sent at:
https://lore.kernel.org/linux-mm/20221108195211.214025-1-flaniel@linux.microsoft.com/

Changes v1 to v2:
- add 'cc:stable', 'Fixes:' and review/ack tags
- update commitmsg and fix my email
- rebase on bpf tree and tag for bpf tree

Thanks!
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
This commit is contained in:
Andrii Nakryiko 2022-11-11 11:44:46 -08:00
parent 5704bc7e89 9cd094829d
commit c20572600e
3 changed files with 13 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
mm/maccess.c
View file

@ -97,7 +97,7 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
return src - unsafe_addr;
Efault:
pagefault_enable();
dst[-1] = '\0';
dst[0] = '\0';
return -EFAULT;
}

7
tools/testing/selftests/bpf/prog_tests/varlen.c
View file

@ -63,6 +63,13 @@ void test_varlen(void)
CHECK_VAL(data->total4, size1 + size2);
CHECK(memcmp(data->payload4, exp_str, size1 + size2), "content_check",
"doesn't match!\n");
CHECK_VAL(bss->ret_bad_read, -EFAULT);
CHECK_VAL(data->payload_bad[0], 0x42);
CHECK_VAL(data->payload_bad[1], 0x42);
CHECK_VAL(data->payload_bad[2], 0);
CHECK_VAL(data->payload_bad[3], 0x42);
CHECK_VAL(data->payload_bad[4], 0x42);
cleanup:
test_varlen__destroy(skel);
}

5
tools/testing/selftests/bpf/progs/test_varlen.c
View file

@ -19,6 +19,7 @@ __u64 payload1_len1 = 0;
__u64 payload1_len2 = 0;
__u64 total1 = 0;
char payload1[MAX_LEN + MAX_LEN] = {};
__u64 ret_bad_read = 0;
/* .data */
int payload2_len1 = -1;
@ -36,6 +37,8 @@ int payload4_len2 = -1;
int total4= -1;
char payload4[MAX_LEN + MAX_LEN] = { 1 };
char payload_bad[5] = { 0x42, 0x42, 0x42, 0x42, 0x42 };
SEC("raw_tp/sys_enter")
int handler64_unsigned(void *regs)
{
@ -61,6 +64,8 @@ int handler64_unsigned(void *regs)
total1 = payload - (void *)payload1;
ret_bad_read = bpf_probe_read_kernel_str(payload_bad + 2, 1, (void *) -1);
return 0;
}