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authorTom Rix <trix@redhat.com>2020-07-13 07:06:34 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2020-07-23 17:34:17 +1000
commitc06c76602e03bde24ee69a2022a829127e504202 (patch)
tree761323430ed7b7bd6cc4bc0e50a6c69c3c49244d /drivers/crypto
parentfd92028e4c0cbbe498cc622369baff6b395e88e6 (diff)
crypto: qat - fix double free in qat_uclo_create_batch_init_list
clang static analysis flags this error qat_uclo.c:297:3: warning: Attempt to free released memory [unix.Malloc] kfree(*init_tab_base); ^~~~~~~~~~~~~~~~~~~~~ When input *init_tab_base is null, the function allocates memory for the head of the list. When there is problem allocating other list elements the list is unwound and freed. Then a check is made if the list head was allocated and is also freed. Keeping track of the what may need to be freed is the variable 'tail_old'. The unwinding/freeing block is while (tail_old) { mem_init = tail_old->next; kfree(tail_old); tail_old = mem_init; } The problem is that the first element of tail_old is also what was allocated for the list head init_header = kzalloc(sizeof(*init_header), GFP_KERNEL); ... *init_tab_base = init_header; flag = 1; } tail_old = init_header; So *init_tab_base/init_header are freed twice. There is another problem. When the input *init_tab_base is non null the tail_old is calculated by traveling down the list to first non null entry. tail_old = init_header; while (tail_old->next) tail_old = tail_old->next; When the unwinding free happens, the last entry of the input list will be freed. So the freeing needs a general changed. If locally allocated the first element of tail_old is freed, else it is skipped. As a bit of cleanup, reset *init_tab_base if it came in as null. Fixes: b4b7e67c917f ("crypto: qat - Intel(R) QAT ucode part of fw loader") Cc: <stable@vger.kernel.org> Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/qat/qat_common/qat_uclo.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/crypto/qat/qat_common/qat_uclo.c b/drivers/crypto/qat/qat_common/qat_uclo.c
index 4cc1f436b075..bff759e2f811 100644
--- a/drivers/crypto/qat/qat_common/qat_uclo.c
+++ b/drivers/crypto/qat/qat_common/qat_uclo.c
@@ -288,13 +288,18 @@ static int qat_uclo_create_batch_init_list(struct icp_qat_fw_loader_handle
}
return 0;
out_err:
+ /* Do not free the list head unless we allocated it. */
+ tail_old = tail_old->next;
+ if (flag) {
+ kfree(*init_tab_base);
+ *init_tab_base = NULL;
+ }
+
while (tail_old) {
mem_init = tail_old->next;
kfree(tail_old);
tail_old = mem_init;
}
- if (flag)
- kfree(*init_tab_base);
return -ENOMEM;
}