[PATCH v4 3/4] zram: validate parameters in each backend's setup_params

[Haoqin Huang]

From: Haoqin Huang <haoqinhuang@xxxxxxxxxxx>

Dict and level parameters are silently accepted even for backends
that do not support them. Validate these parameters in each backend's
.setup_params() to reject unsupported combinations and out-of-range
levels with a specific error message.

Signed-off-by: Haoqin Huang <haoqinhuang@xxxxxxxxxxx>
Signed-off-by: Rongwei Wang <zigiwang@xxxxxxxxxxx>
---
 drivers/block/zram/backend_842.c     | 8 ++++++++
 drivers/block/zram/backend_deflate.c | 9 +++++++++
 drivers/block/zram/backend_lz4.c     | 5 +++++
 drivers/block/zram/backend_lz4hc.c   | 5 +++++
 drivers/block/zram/backend_lzo.c     | 8 ++++++++
 drivers/block/zram/backend_lzorle.c  | 8 ++++++++
 drivers/block/zram/backend_zstd.c    | 5 +++++
 7 files changed, 48 insertions(+)

diff --git a/drivers/block/zram/backend_842.c b/drivers/block/zram/backend_842.c
index 10d9d5c60f53..91a22313fe82 100644
--- a/drivers/block/zram/backend_842.c
+++ b/drivers/block/zram/backend_842.c
@@ -13,6 +13,14 @@ static void release_params_842(struct zcomp_params *params)
 
 static int setup_params_842(struct zcomp_params *params)
 {
+	if (params->dict_sz) {
+		pr_err("842: dictionary is not supported\n");
+		return -EOPNOTSUPP;
+	}
+	if (params->level != ZCOMP_PARAM_NOT_SET) {
+		pr_err("842: compression level is not supported\n");
+		return -EOPNOTSUPP;
+	}
 	return 0;
 }
 
diff --git a/drivers/block/zram/backend_deflate.c b/drivers/block/zram/backend_deflate.c
index f92a52a720d1..1a2be462bc67 100644
--- a/drivers/block/zram/backend_deflate.c
+++ b/drivers/block/zram/backend_deflate.c
@@ -22,8 +22,17 @@ static void deflate_release_params(struct zcomp_params *params)
 
 static int deflate_setup_params(struct zcomp_params *params)
 {
+	if (params->dict_sz) {
+		pr_err("deflate: dictionary is not supported\n");
+		return -EOPNOTSUPP;
+	}
 	if (params->level == ZCOMP_PARAM_NOT_SET)
 		params->level = Z_DEFAULT_COMPRESSION;
+	else if (params->level < Z_DEFAULT_COMPRESSION ||
+		 params->level > Z_BEST_COMPRESSION) {
+		pr_err("deflate: invalid compression level %d\n", params->level);
+		return -EINVAL;
+	}
 	if (params->deflate.winbits == ZCOMP_PARAM_NOT_SET)
 		params->deflate.winbits = DEFLATE_DEF_WINBITS;
 
diff --git a/drivers/block/zram/backend_lz4.c b/drivers/block/zram/backend_lz4.c
index c449d511ba86..6577b484941a 100644
--- a/drivers/block/zram/backend_lz4.c
+++ b/drivers/block/zram/backend_lz4.c
@@ -30,6 +30,11 @@ static int lz4_setup_params(struct zcomp_params *params)
 
 	if (params->level == ZCOMP_PARAM_NOT_SET)
 		params->level = LZ4_ACCELERATION_DEFAULT;
+	else if (params->level < LZ4_ACCELERATION_DEFAULT ||
+		 params->level > U16_MAX) {
+		pr_err("lz4: invalid compression level %d\n", params->level);
+		return -EINVAL;
+	}
 
 	if (!params->dict || !params->dict_sz)
 		return 0;
diff --git a/drivers/block/zram/backend_lz4hc.c b/drivers/block/zram/backend_lz4hc.c
index f6a336acfe20..5d551d165213 100644
--- a/drivers/block/zram/backend_lz4hc.c
+++ b/drivers/block/zram/backend_lz4hc.c
@@ -20,6 +20,11 @@ static int lz4hc_setup_params(struct zcomp_params *params)
 {
 	if (params->level == ZCOMP_PARAM_NOT_SET)
 		params->level = LZ4HC_DEFAULT_CLEVEL;
+	else if (params->level < LZ4HC_MIN_CLEVEL ||
+		 params->level > LZ4HC_MAX_CLEVEL) {
+		pr_err("lz4hc: invalid compression level %d\n", params->level);
+		return -EINVAL;
+	}
 
 	return 0;
 }
diff --git a/drivers/block/zram/backend_lzo.c b/drivers/block/zram/backend_lzo.c
index 4c906beaae6b..cdbb89aaa0de 100644
--- a/drivers/block/zram/backend_lzo.c
+++ b/drivers/block/zram/backend_lzo.c
@@ -12,6 +12,14 @@ static void lzo_release_params(struct zcomp_params *params)
 
 static int lzo_setup_params(struct zcomp_params *params)
 {
+	if (params->dict_sz) {
+		pr_err("lzo: dictionary is not supported\n");
+		return -EOPNOTSUPP;
+	}
+	if (params->level != ZCOMP_PARAM_NOT_SET) {
+		pr_err("lzo: compression level is not supported\n");
+		return -EOPNOTSUPP;
+	}
 	return 0;
 }
 
diff --git a/drivers/block/zram/backend_lzorle.c b/drivers/block/zram/backend_lzorle.c
index 10640c96cbfc..58f7ddf5a55f 100644
--- a/drivers/block/zram/backend_lzorle.c
+++ b/drivers/block/zram/backend_lzorle.c
@@ -12,6 +12,14 @@ static void lzorle_release_params(struct zcomp_params *params)
 
 static int lzorle_setup_params(struct zcomp_params *params)
 {
+	if (params->dict_sz) {
+		pr_err("lzo-rle: dictionary is not supported\n");
+		return -EOPNOTSUPP;
+	}
+	if (params->level != ZCOMP_PARAM_NOT_SET) {
+		pr_err("lzo-rle: compression level is not supported\n");
+		return -EOPNOTSUPP;
+	}
 	return 0;
 }
 
diff --git a/drivers/block/zram/backend_zstd.c b/drivers/block/zram/backend_zstd.c
index 2584f47c9b3c..4d19d6089f13 100644
--- a/drivers/block/zram/backend_zstd.c
+++ b/drivers/block/zram/backend_zstd.c
@@ -60,6 +60,11 @@ static int zstd_setup_params(struct zcomp_params *params)
 	params->drv_data = zp;
 	if (params->level == ZCOMP_PARAM_NOT_SET)
 		params->level = zstd_default_clevel();
+	else if (params->level < zstd_min_clevel() ||
+		 params->level > zstd_max_clevel()) {
+		pr_err("zstd: invalid compression level %d\n", params->level);
+		goto error;
+	}
 
 	zp->cprm = zstd_get_params(params->level, PAGE_SIZE);
 
-- 
2.43.7