[PATCH 01/12] target: Avoid mem leak and needless work in transport_generic_get_mem

Nicholas A. Bellinger
2011-02-04T06:45:14Z

From: Jesper Juhl <jj@chaosbits.net>

In drivers/target/target_core_transport.c::transport_generic_get_mem()
there are a few potential memory leaks in the error paths. This patch
makes sure that we free previously allocated memory when other allocations
fail. It also moves some work (INIT_LIST_HEAD() and assignment to
se_mem->se_len) below all the allocations so that if something fails we
don't do the work at all.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
---
drivers/target/target_core_transport.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index ddc1f7f..04f6115 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -4333,11 +4333,9 @@ transport_generic_get_mem(struct se_cmd *cmd, u32 length, u32 dma_size)
printk(KERN_ERR "Unable to allocate struct se_mem\n");
goto out;
}
- INIT_LIST_HEAD(&se_mem->se_list);
- se_mem->se_len = (length > dma_size) ? dma_size : length;

/* #warning FIXME Allocate contigous pages for struct se_mem elements */
- se_mem->se_page = (struct page *) alloc_pages(GFP_KERNEL, 0);
+ se_mem->se_page = alloc_pages(GFP_KERNEL, 0);
if (!(se_mem->se_page)) {
printk(KERN_ERR "alloc_pages() failed\n");
goto out;
@@ -4348,6 +4346,8 @@ transport_generic_get_mem(struct se_cmd *cmd, u32 length, u32 dma_size)
printk(KERN_ERR "kmap_atomic() failed\n");
goto out;
}
+ INIT_LIST_HEAD(&se_mem->se_list);
+ se_mem->se_len = (length > dma_size) ? dma_size : length;
memset(buf, 0, se_mem->se_len);
kunmap_atomic(buf, KM_IRQ0);

@@ -4366,6 +4366,9 @@ transport_generic_get_mem(struct se_cmd *cmd, u32 length, u32 dma_size)

return 0;
out:
+ if (se_mem)
+ __free_pages(se_mem->se_page, 0);
+ kmem_cache_free(se_mem_cache, se_mem);
return -1;
}

--
1.7.4