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| author | Guillermo Julián Moreno <guillermo.julian@naudit.es> | 2016-06-03 14:55:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-03 15:06:22 -0700 |
| commit | 65ee03c4b9f89e1b088defd97273be6da169d798 (patch) | |
| tree | ca5bd05b3bc29cf2a5a07f083fd80221049aa06e | |
| parent | 4340fa55298d17049e71c7a34e04647379c269f3 (diff) | |
| download | linux-65ee03c4b9f89e1b088defd97273be6da169d798.tar.gz linux-65ee03c4b9f89e1b088defd97273be6da169d798.tar.bz2 linux-65ee03c4b9f89e1b088defd97273be6da169d798.zip | |
mm: fix overflow in vm_map_ram()
When remapping pages accounting for 4G or more memory space, the
operation 'count << PAGE_SHIFT' overflows as it is performed on an
integer. Solution: cast before doing the bitshift.
[akpm@linux-foundation.org: fix vm_unmap_ram() also]
[akpm@linux-foundation.org: fix vmap() as well, per Guillermo]
Link: http://lkml.kernel.org/r/etPan.57175fb3.7a271c6b.2bd@naudit.es
Signed-off-by: Guillermo Julián Moreno <guillermo.julian@naudit.es>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/vmalloc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index cf7ad1a53be0..e11475cdeb7a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1105,7 +1105,7 @@ EXPORT_SYMBOL_GPL(vm_unmap_aliases); */ void vm_unmap_ram(const void *mem, unsigned int count) { - unsigned long size = count << PAGE_SHIFT; + unsigned long size = (unsigned long)count << PAGE_SHIFT; unsigned long addr = (unsigned long)mem; BUG_ON(!addr); @@ -1140,7 +1140,7 @@ EXPORT_SYMBOL(vm_unmap_ram); */ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) { - unsigned long size = count << PAGE_SHIFT; + unsigned long size = (unsigned long)count << PAGE_SHIFT; unsigned long addr; void *mem; @@ -1574,14 +1574,15 @@ void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) { struct vm_struct *area; + unsigned long size; /* In bytes */ might_sleep(); if (count > totalram_pages) return NULL; - area = get_vm_area_caller((count << PAGE_SHIFT), flags, - __builtin_return_address(0)); + size = (unsigned long)count << PAGE_SHIFT; + area = get_vm_area_caller(size, flags, __builtin_return_address(0)); if (!area) return NULL; |