Messages in this thread Patch in this message | | | From | Elena Reshetova <> | Subject | [PATCH 2/5] fs, xfs: convert xfs_efi_log_item.efi_refcount from atomic_t to refcount_t | Date | Wed, 8 Mar 2017 10:53:36 +0200 |
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refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> --- fs/xfs/xfs_extfree_item.c | 4 ++-- fs/xfs/xfs_extfree_item.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c index d7bc149..4e0acf0 100644 --- a/fs/xfs/xfs_extfree_item.c +++ b/fs/xfs/xfs_extfree_item.c @@ -220,7 +220,7 @@ xfs_efi_init( efip->efi_format.efi_nextents = nextents; efip->efi_format.efi_id = (uintptr_t)(void *)efip; atomic_set(&efip->efi_next_extent, 0); - atomic_set(&efip->efi_refcount, 2); + refcount_set(&efip->efi_refcount, 2); return efip; } @@ -290,7 +290,7 @@ void xfs_efi_release( struct xfs_efi_log_item *efip) { - if (atomic_dec_and_test(&efip->efi_refcount)) { + if (refcount_dec_and_test(&efip->efi_refcount)) { xfs_trans_ail_remove(&efip->efi_item, SHUTDOWN_LOG_IO_ERROR); xfs_efi_item_free(efip); } diff --git a/fs/xfs/xfs_extfree_item.h b/fs/xfs/xfs_extfree_item.h index a32c794..fadf736 100644 --- a/fs/xfs/xfs_extfree_item.h +++ b/fs/xfs/xfs_extfree_item.h @@ -64,7 +64,7 @@ struct kmem_zone; */ typedef struct xfs_efi_log_item { xfs_log_item_t efi_item; - atomic_t efi_refcount; + refcount_t efi_refcount; atomic_t efi_next_extent; unsigned long efi_flags; /* misc flags */ xfs_efi_log_format_t efi_format; -- 2.7.4
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