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| author | Heiko Carstens <hca@linux.ibm.com> | 2025-06-16 17:00:32 +0200 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2025-06-29 13:12:02 +0200 |
| commit | d2b73ce90a7141d5aa34a52de82d69fbb68efc30 (patch) | |
| tree | 1f2f759500a1d4f59a94907375deb19e7933c3ef /arch/s390/lib | |
| parent | s390/uaccess: Initialize code pages executed with non-default access key (diff) | |
| download | linux-d2b73ce90a7141d5aa34a52de82d69fbb68efc30.tar.gz linux-d2b73ce90a7141d5aa34a52de82d69fbb68efc30.zip | |
s390/uaccess: Prevent kprobes on cmpxchg_user_key() functions
Code regions within cmpxchg_user_key() functions may be executed with a
non-default access key, which may lead to a protection exception if the
corresponding page has the fetch-protection bit enabled.
There is code in place which initializes the storage keys of such pages
when needed. However there is also the possibility of out-of-line execution
of such code in case a kprobe is set within such a region.
To avoid this problem prevent that any kprobe can be set within the
cmpxchg_user_key() functions.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'arch/s390/lib')
| -rw-r--r-- | arch/s390/lib/uaccess.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index 02359c03b809..750360cce02c 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -8,6 +8,7 @@ * Gerald Schaefer (gerald.schaefer@de.ibm.com) */ +#include <linux/kprobes.h> #include <linux/uaccess.h> #include <linux/export.h> #include <linux/mm.h> @@ -149,8 +150,8 @@ EXPORT_SYMBOL(_copy_to_user_key); #define CMPXCHG_USER_KEY_MAX_LOOPS 128 -int __cmpxchg_user_key1(unsigned long address, unsigned char *uval, - unsigned char old, unsigned char new, unsigned long key) +int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval, + unsigned char old, unsigned char new, unsigned long key) { unsigned int prev, shift, mask, _old, _new; unsigned long count; @@ -208,8 +209,8 @@ int __cmpxchg_user_key1(unsigned long address, unsigned char *uval, } EXPORT_SYMBOL(__cmpxchg_user_key1); -int __cmpxchg_user_key2(unsigned long address, unsigned short *uval, - unsigned short old, unsigned short new, unsigned long key) +int __kprobes __cmpxchg_user_key2(unsigned long address, unsigned short *uval, + unsigned short old, unsigned short new, unsigned long key) { unsigned int prev, shift, mask, _old, _new; unsigned long count; @@ -267,8 +268,8 @@ int __cmpxchg_user_key2(unsigned long address, unsigned short *uval, } EXPORT_SYMBOL(__cmpxchg_user_key2); -int __cmpxchg_user_key4(unsigned long address, unsigned int *uval, - unsigned int old, unsigned int new, unsigned long key) +int __kprobes __cmpxchg_user_key4(unsigned long address, unsigned int *uval, + unsigned int old, unsigned int new, unsigned long key) { unsigned int prev = old; bool sacf_flag; @@ -299,8 +300,8 @@ int __cmpxchg_user_key4(unsigned long address, unsigned int *uval, } EXPORT_SYMBOL(__cmpxchg_user_key4); -int __cmpxchg_user_key8(unsigned long address, unsigned long *uval, - unsigned long old, unsigned long new, unsigned long key) +int __kprobes __cmpxchg_user_key8(unsigned long address, unsigned long *uval, + unsigned long old, unsigned long new, unsigned long key) { unsigned long prev = old; bool sacf_flag; @@ -331,8 +332,8 @@ int __cmpxchg_user_key8(unsigned long address, unsigned long *uval, } EXPORT_SYMBOL(__cmpxchg_user_key8); -int __cmpxchg_user_key16(unsigned long address, __uint128_t *uval, - __uint128_t old, __uint128_t new, unsigned long key) +int __kprobes __cmpxchg_user_key16(unsigned long address, __uint128_t *uval, + __uint128_t old, __uint128_t new, unsigned long key) { __uint128_t prev = old; bool sacf_flag; |