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authorGeert Uytterhoeven <geert+renesas@glider.be>2019-10-21 16:23:09 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2019-11-05 12:29:27 +0100
commit3b05a1e517e1a8cfda4866ec31d28b2bc4fee4c4 (patch)
treed200d724507722b1c5bf0aa7de17fe3db7dfe8b0 /arch/powerpc/kernel
parentpowerpc/book3s64/hash: Add cond_resched to avoid soft lockup warning (diff)
downloadlinux-3b05a1e517e1a8cfda4866ec31d28b2bc4fee4c4.tar.xz
linux-3b05a1e517e1a8cfda4866ec31d28b2bc4fee4c4.zip
powerpc/security: Fix debugfs data leak on 32-bit
"powerpc_security_features" is "unsigned long", i.e. 32-bit or 64-bit, depending on the platform (PPC_FSL_BOOK3E or PPC_BOOK3S_64). Hence casting its address to "u64 *", and calling debugfs_create_x64() is wrong, and leaks 32-bit of nearby data to userspace on 32-bit platforms. While all currently defined SEC_FTR_* security feature flags fit in 32-bit, they all have "ULL" suffixes to make them 64-bit constants. Hence fix the leak by changing the type of "powerpc_security_features" (and the parameter types of its accessors) to "u64". This also allows to drop the cast. Fixes: 398af571128fe75f ("powerpc/security: Show powerpc_security_features in debugfs") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191021142309.28105-1-geert+renesas@glider.be
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r--arch/powerpc/kernel/security.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index ad7f4bf8447c..a3021e6faed8 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -16,7 +16,7 @@
#include <asm/setup.h>
-unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
+u64 powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
enum count_cache_flush_type {
COUNT_CACHE_FLUSH_NONE = 0x1,
@@ -108,7 +108,7 @@ device_initcall(barrier_nospec_debugfs_init);
static __init int security_feature_debugfs_init(void)
{
debugfs_create_x64("security_features", 0400, powerpc_debugfs_root,
- (u64 *)&powerpc_security_features);
+ &powerpc_security_features);
return 0;
}
device_initcall(security_feature_debugfs_init);