Commit 7d41c03e authored by Wei Yang's avatar Wei Yang Committed by Linus Torvalds

mm/memblock.c: check return value of memblock_reserve() in memblock_virt_alloc_internal()

memblock_reserve() would add a new range to memblock.reserved in case
the new range is not totally covered by any of the current
memblock.reserved range.  If the memblock.reserved is full and can't
resize, memblock_reserve() would fail.

This doesn't happen in real world now, I observed this during code
review.  While theoretically, it has the chance to happen.  And if it
happens, others would think this range of memory is still available and
may corrupt the memory.

This patch checks the return value and goto "done" after it succeeds.

Link: http://lkml.kernel.org/r/1482363033-24754-3-git-send-email-richard.weiyang@gmail.comSigned-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ef415ef4
...@@ -1299,18 +1299,17 @@ static void * __init memblock_virt_alloc_internal( ...@@ -1299,18 +1299,17 @@ static void * __init memblock_virt_alloc_internal(
if (max_addr > memblock.current_limit) if (max_addr > memblock.current_limit)
max_addr = memblock.current_limit; max_addr = memblock.current_limit;
again: again:
alloc = memblock_find_in_range_node(size, align, min_addr, max_addr, alloc = memblock_find_in_range_node(size, align, min_addr, max_addr,
nid, flags); nid, flags);
if (alloc) if (alloc && !memblock_reserve(alloc, size))
goto done; goto done;
if (nid != NUMA_NO_NODE) { if (nid != NUMA_NO_NODE) {
alloc = memblock_find_in_range_node(size, align, min_addr, alloc = memblock_find_in_range_node(size, align, min_addr,
max_addr, NUMA_NO_NODE, max_addr, NUMA_NO_NODE,
flags); flags);
if (alloc) if (alloc && !memblock_reserve(alloc, size))
goto done; goto done;
} }
...@@ -1328,7 +1327,6 @@ static void * __init memblock_virt_alloc_internal( ...@@ -1328,7 +1327,6 @@ static void * __init memblock_virt_alloc_internal(
return NULL; return NULL;
done: done:
memblock_reserve(alloc, size);
ptr = phys_to_virt(alloc); ptr = phys_to_virt(alloc);
memset(ptr, 0, size); memset(ptr, 0, size);
......
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