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authorPhilippe Mathieu-Daudé <philmd@redhat.com>2023-08-11 18:47:50 +0100
committerKlaus Jensen <k.jensen@samsung.com>2023-09-12 16:17:05 +0200
commitb02c2a85a6c8e5ecc1bfca1ef794b5897c9ebad3 (patch)
tree5d888137ea529ae87029b3d0cd9f39cb9e7d26eb /hw/nvme
parent9ef497755afc252fb8e060c9ea6b0987abfd20b6 (diff)
hw/nvme: Use #define to avoid variable length array
In nvme_map_sgl() we create an array segment[] whose size is the 'const int SEG_CHUNK_SIZE'. Since this is C, rather than C++, a "const int foo" is not a true constant, it's merely a variable with a constant value, and so semantically segment[] is a variable-length array. Switch SEG_CHUNK_SIZE to a #define so that we can make the segment[] array truly fixed-size, in the sense that it doesn't trigger the -Wvla warning. The codebase has very few VLAs, and if we can get rid of them all we can make the compiler error on new additions. This is a defensive measure against security bugs where an on-stack dynamic allocation isn't correctly size-checked (e.g. CVE-2021-3527). [PMM: rebased (function has moved file), expand commit message based on discussion from previous version of patch] Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Diffstat (limited to 'hw/nvme')
-rw-r--r--hw/nvme/ctrl.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 539d273553..d99a6f5c9a 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -1045,7 +1045,7 @@ static uint16_t nvme_map_sgl(NvmeCtrl *n, NvmeSg *sg, NvmeSglDescriptor sgl,
* descriptors and segment chain) than the command transfer size, so it is
* not bounded by MDTS.
*/
- const int SEG_CHUNK_SIZE = 256;
+#define SEG_CHUNK_SIZE 256
NvmeSglDescriptor segment[SEG_CHUNK_SIZE], *sgld, *last_sgld;
uint64_t nsgld;