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authorLiu ShuoX <shuox.liu@intel.com>2014-03-12 21:24:44 +0800
committerTony Luck <tony.luck@intel.com>2014-03-17 14:14:03 -0700
commit017321cf390045dd4c4afc4a232995ea50bcf66d (patch)
treec7ce8487792ba20f6e07d3320e4985e331fbf921 /fs/pstore
parent34f0ec82e0a99009161a281629280cfcad187696 (diff)
downloadop-kernel-dev-017321cf390045dd4c4afc4a232995ea50bcf66d.zip
op-kernel-dev-017321cf390045dd4c4afc4a232995ea50bcf66d.tar.gz
pstore: Fix buffer overflow while write offset equal to buffer size
In case new offset is equal to prz->buffer_size, it won't wrap at this time and will return old(overflow) value next time. Signed-off-by: Liu ShuoX <shuox.liu@intel.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'fs/pstore')
-rw-r--r--fs/pstore/ram_core.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index de272d4..ff7e3d4 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -54,7 +54,7 @@ static size_t buffer_start_add_atomic(struct persistent_ram_zone *prz, size_t a)
do {
old = atomic_read(&prz->buffer->start);
new = old + a;
- while (unlikely(new > prz->buffer_size))
+ while (unlikely(new >= prz->buffer_size))
new -= prz->buffer_size;
} while (atomic_cmpxchg(&prz->buffer->start, old, new) != old);
@@ -91,7 +91,7 @@ static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a)
old = atomic_read(&prz->buffer->start);
new = old + a;
- while (unlikely(new > prz->buffer_size))
+ while (unlikely(new >= prz->buffer_size))
new -= prz->buffer_size;
atomic_set(&prz->buffer->start, new);
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