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| author | Arnd Bergmann <arnd@arndb.de> | 2022-02-10 16:24:30 +0100 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2022-02-14 22:30:53 +0100 |
| commit | 222ca305c9fd39e5ed8104da25c09b2b79a516a8 (patch) | |
| tree | 226513c6b142c9fab9582d776f77d00e2cbee47c /arch/microblaze | |
| parent | Linux 5.17-rc3 (diff) | |
| download | linux-222ca305c9fd39e5ed8104da25c09b2b79a516a8.tar.xz linux-222ca305c9fd39e5ed8104da25c09b2b79a516a8.zip | |
uaccess: fix integer overflow on access_ok()
Three architectures check the end of a user access against the
address limit without taking a possible overflow into account.
Passing a negative length or another overflow in here returns
success when it should not.
Use the most common correct implementation here, which optimizes
for a constant 'size' argument, and turns the common case into a
single comparison.
Cc: stable@vger.kernel.org
Fixes: da551281947c ("csky: User access")
Fixes: f663b60f5215 ("microblaze: Fix uaccess_ok macro")
Fixes: 7567746e1c0d ("Hexagon: Add user access functions")
Reported-by: David Laight <David.Laight@aculab.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/microblaze')
| -rw-r--r-- | arch/microblaze/include/asm/uaccess.h | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h index d2a8ef9f8978..5b6e0e7788f4 100644 --- a/arch/microblaze/include/asm/uaccess.h +++ b/arch/microblaze/include/asm/uaccess.h @@ -39,24 +39,13 @@ # define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) -static inline int access_ok(const void __user *addr, unsigned long size) +static inline int __access_ok(unsigned long addr, unsigned long size) { - if (!size) - goto ok; + unsigned long limit = user_addr_max(); - if ((get_fs().seg < ((unsigned long)addr)) || - (get_fs().seg < ((unsigned long)addr + size - 1))) { - pr_devel("ACCESS fail at 0x%08x (size 0x%x), seg 0x%08x\n", - (__force u32)addr, (u32)size, - (u32)get_fs().seg); - return 0; - } -ok: - pr_devel("ACCESS OK at 0x%08x (size 0x%x), seg 0x%08x\n", - (__force u32)addr, (u32)size, - (u32)get_fs().seg); - return 1; + return (size <= limit) && (addr <= (limit - size)); } +#define access_ok(addr, size) __access_ok((unsigned long)addr, size) # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" |