diff options
author | Ingo Molnar <mingo@kernel.org> | 2017-09-23 15:59:52 +0300 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2017-09-24 14:04:32 +0300 |
commit | 6ff15f8db7eaf29ef5ead6afbec9b25485fe8703 (patch) | |
tree | 63194abd2d85169c91cb6eed9fe45290491b76f0 /arch/x86/kernel/fpu | |
parent | 56583c9a1400fe1935edd55b24b4fbbc779b59cb (diff) | |
download | linux-6ff15f8db7eaf29ef5ead6afbec9b25485fe8703.tar.xz |
x86/fpu: Change 'size_total' parameter to unsigned and standardize the size checks in copy_xstate_to_*()
'size_total' is derived from an unsigned input parameter - and then converted
to 'int' and checked for negative ranges:
if (size_total < 0 || offset < size_total) {
This conversion and the checks are unnecessary obfuscation, reject overly
large requested copy sizes outright and simplify the underlying code.
Reported-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-10-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/fpu')
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 32 |
1 files changed, 15 insertions, 17 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index c13083579655..b18c5457065a 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -925,15 +925,11 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, * the source data pointer or increment pos, count, kbuf, and ubuf. */ static inline int -__copy_xstate_to_kernel(void *kbuf, - const void *data, - unsigned int offset, unsigned int size, int size_total) +__copy_xstate_to_kernel(void *kbuf, const void *data, + unsigned int offset, unsigned int size, unsigned int size_total) { - if (!size) - return 0; - - if (size_total < 0 || offset < size_total) { - unsigned int copy = size_total < 0 ? size : min(size, size_total - offset); + if (offset < size_total) { + unsigned int copy = min(size, size_total - offset); memcpy(kbuf + offset, data, copy); } @@ -986,12 +982,13 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of offset = xstate_offsets[i]; size = xstate_sizes[i]; + /* The next component has to fit fully into the output buffer: */ + if (offset + size > size_total) + break; + ret = __copy_xstate_to_kernel(kbuf, src, offset, size, size_total); if (ret) return ret; - - if (offset + size >= size_total) - break; } } @@ -1010,13 +1007,13 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of } static inline int -__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, int size_total) +__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, unsigned int size_total) { if (!size) return 0; - if (size_total < 0 || offset < size_total) { - unsigned int copy = size_total < 0 ? size : min(size, size_total - offset); + if (offset < size_total) { + unsigned int copy = min(size, size_total - offset); if (__copy_to_user(ubuf + offset, data, copy)) return -EFAULT; @@ -1069,12 +1066,13 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i offset = xstate_offsets[i]; size = xstate_sizes[i]; + /* The next component has to fit fully into the output buffer: */ + if (offset + size > size_total) + break; + ret = __copy_xstate_to_user(ubuf, src, offset, size, size_total); if (ret) return ret; - - if (offset + size >= size_total) - break; } } |