From 5981c245a890db6a6e16fb6d3838cc9fc9fdf0ff Mon Sep 17 00:00:00 2001 From: Elena Reshetova Date: Mon, 6 Mar 2017 16:21:11 +0200 Subject: [PATCH] target/iblock: convert iblock_req.pending from atomic_t to refcount_t 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_iblock.c | 12 ++++++------ drivers/target/target_core_iblock.h | 3 ++- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index d316ed5..bb069eb 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -279,7 +279,7 @@ static void iblock_complete_cmd(struct se_cmd *cmd) struct iblock_req *ibr = cmd->priv; u8 status; - if (!atomic_dec_and_test(&ibr->pending)) + if (!refcount_dec_and_test(&ibr->pending)) return; if (atomic_read(&ibr->ib_bio_err_cnt)) @@ -487,7 +487,7 @@ iblock_execute_write_same(struct se_cmd *cmd) bio_list_init(&list); bio_list_add(&list, bio); - atomic_set(&ibr->pending, 1); + refcount_set(&ibr->pending, 1); while (sectors) { while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) @@ -498,7 +498,7 @@ iblock_execute_write_same(struct se_cmd *cmd) if (!bio) goto fail_put_bios; - atomic_inc(&ibr->pending); + refcount_inc(&ibr->pending); bio_list_add(&list, bio); } @@ -706,7 +706,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, cmd->priv = ibr; if (!sgl_nents) { - atomic_set(&ibr->pending, 1); + refcount_set(&ibr->pending, 1); iblock_complete_cmd(cmd); return 0; } @@ -719,7 +719,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, bio_list_init(&list); bio_list_add(&list, bio); - atomic_set(&ibr->pending, 2); + refcount_set(&ibr->pending, 2); bio_cnt = 1; for_each_sg(sgl, sg, sgl_nents, i) { @@ -740,7 +740,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, if (!bio) goto fail_put_bios; - atomic_inc(&ibr->pending); + refcount_inc(&ibr->pending); bio_list_add(&list, bio); bio_cnt++; } diff --git a/drivers/target/target_core_iblock.h b/drivers/target/target_core_iblock.h index 718d3fc..f2a5797 100644 --- a/drivers/target/target_core_iblock.h +++ b/drivers/target/target_core_iblock.h @@ -2,6 +2,7 @@ #define TARGET_CORE_IBLOCK_H #include +#include #include #define IBLOCK_VERSION "4.0" @@ -10,7 +11,7 @@ #define IBLOCK_LBA_SHIFT 9 struct iblock_req { - atomic_t pending; + refcount_t pending; atomic_t ib_bio_err_cnt; } ____cacheline_aligned; -- 2.7.4