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| author | Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> | 2018-07-04 20:57:02 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-12-17 01:08:38 +0300 |
| commit | 20a334b403478c0fe7e4f27712b645f5a51174b2 (patch) | |
| tree | 823b472ec88bd2c3abde5fc0bbf22cf0154d5b84 | |
| parent | 29002321516dd7a79e4840d3800a86f2aaa070c3 (diff) | |
| download | linux-20a334b403478c0fe7e4f27712b645f5a51174b2.tar.xz | |
powerpc/pseries: Avoid using the size greater than RTAS_ERROR_LOG_MAX.
commit 74e96bf44f430cf7a01de19ba6cf49b361cdfd6e upstream.
The global mce data buffer that used to copy rtas error log is of 2048
(RTAS_ERROR_LOG_MAX) bytes in size. Before the copy we read
extended_log_length from rtas error log header, then use max of
extended_log_length and RTAS_ERROR_LOG_MAX as a size of data to be copied.
Ideally the platform (phyp) will never send extended error log with
size > 2048. But if that happens, then we have a risk of buffer overrun
and corruption. Fix this by using min_t instead.
Fixes: d368514c3097 ("powerpc: Fix corruption when grabbing FWNMI data")
Reported-by: Michal Suchanek <msuchanek@suse.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/powerpc/platforms/pseries/ras.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c index 55cbad443500..02d9e5f323fb 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -309,7 +309,7 @@ static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) int len, error_log_length; error_log_length = 8 + rtas_error_extended_log_length(h); - len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX); + len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX); memcpy(global_mce_data_buf, h, len); errhdr = (struct rtas_error_log *)global_mce_data_buf; |