diff options
| author | Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> | 2018-07-04 23:27:02 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-15 09:43:00 +0200 |
| commit | 5cb808572c23db828f2ac35c0c1e7088aef5ec03 (patch) | |
| tree | 2990630a9b6d7c6ff643025c718bf3bd0cad3948 | |
| parent | 7aed5a52b85f345370501b95ec44ebab5b40f043 (diff) | |
powerpc/pseries: Avoid using the size greater than RTAS_ERROR_LOG_MAX.
[ Upstream commit 74e96bf44f430cf7a01de19ba6cf49b361cdfd6e ]
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: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 34989ce43147..8799d8a83d56 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -357,7 +357,7 @@ 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; |