3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> commit bcf4dd5f9ee096bd1510f838dd4750c35df4e38b upstream. The test_fp_ctl function is used to test if a given value is a valid floating-point control. The inline assembly in test_fp_ctl uses an incorrect constraint for the 'orig_fpc' variable. If the compiler chooses the same register for 'fpc' and 'orig_fpc' the test_fp_ctl() function always returns true. This allows user space to trigger kernel oopses with invalid floating-point control values on the signal stack. This problem has been introduced with git commit 4725c86055f5bbdcdf "s390: fix save and restore of the floating-point-control register" Reviewed-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- arch/s390/include/asm/switch_to.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/s390/include/asm/switch_to.h +++ b/arch/s390/include/asm/switch_to.h @@ -28,7 +28,7 @@ static inline int test_fp_ctl(u32 fpc) " la %0,0\n" "1:\n" EX_TABLE(0b,1b) - : "=d" (rc), "=d" (orig_fpc) + : "=d" (rc), "=&d" (orig_fpc) : "d" (fpc), "0" (-EINVAL)); return rc; } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html