[SRU][N][PATCH 1/2] f2fs: check validation of fault attrs in f2fs_build_fault_attr()

[Massimiliano Pellizzer]

From: Chao Yu <chao at kernel.org>

[ Upstream commit 4ed886b187f47447ad559619c48c086f432d2b77 ]

- It missed to check validation of fault attrs in parse_options(),
let's fix to add check condition in f2fs_build_fault_attr().
- Use f2fs_build_fault_attr() in __sbi_store() to clean up code.

Signed-off-by: Chao Yu <chao at kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk at kernel.org>
Signed-off-by: Sasha Levin <sashal at kernel.org>
(cherry picked from commit ecb641f424d6d1f055d149a15b892edcc92c504b linux-6.9.y)
CVE-2024-42160
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer at canonical.com>
---
 fs/f2fs/f2fs.h  | 12 ++++++++----
 fs/f2fs/super.c | 27 ++++++++++++++++++++-------
 fs/f2fs/sysfs.c | 14 ++++++++++----
 3 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 1c39ac9de901..ec544ab5307d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -69,7 +69,7 @@ enum {
 
 struct f2fs_fault_info {
 	atomic_t inject_ops;
-	unsigned int inject_rate;
+	int inject_rate;
 	unsigned int inject_type;
 };
 
@@ -4603,10 +4603,14 @@ static inline bool f2fs_need_verity(const struct inode *inode, pgoff_t idx)
 }
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-extern void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate,
-							unsigned int type);
+extern int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
+							unsigned long type);
 #else
-#define f2fs_build_fault_attr(sbi, rate, type)		do { } while (0)
+static int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
+							unsigned long type)
+{
+	return 0;
+}
 #endif
 
 static inline bool is_journalled_quota(struct f2fs_sb_info *sbi)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index fd5dca1e5063..c363e0a4c7e8 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -64,21 +64,31 @@ const char *f2fs_fault_name[FAULT_MAX] = {
 	[FAULT_BLKADDR]		= "invalid blkaddr",
 };
 
-void f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned int rate,
-							unsigned int type)
+int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
+							unsigned long type)
 {
 	struct f2fs_fault_info *ffi = &F2FS_OPTION(sbi).fault_info;
 
 	if (rate) {
+		if (rate > INT_MAX)
+			return -EINVAL;
 		atomic_set(&ffi->inject_ops, 0);
-		ffi->inject_rate = rate;
+		ffi->inject_rate = (int)rate;
 	}
 
-	if (type)
-		ffi->inject_type = type;
+	if (type) {
+		if (type >= BIT(FAULT_MAX))
+			return -EINVAL;
+		ffi->inject_type = (unsigned int)type;
+	}
 
 	if (!rate && !type)
 		memset(ffi, 0, sizeof(struct f2fs_fault_info));
+	else
+		f2fs_info(sbi,
+			"build fault injection attr: rate: %lu, type: 0x%lx",
+								rate, type);
+	return 0;
 }
 #endif
 
@@ -884,14 +894,17 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 		case Opt_fault_injection:
 			if (args->from && match_int(args, &arg))
 				return -EINVAL;
-			f2fs_build_fault_attr(sbi, arg, F2FS_ALL_FAULT_TYPE);
+			if (f2fs_build_fault_attr(sbi, arg,
+					F2FS_ALL_FAULT_TYPE))
+				return -EINVAL;
 			set_opt(sbi, FAULT_INJECTION);
 			break;
 
 		case Opt_fault_type:
 			if (args->from && match_int(args, &arg))
 				return -EINVAL;
-			f2fs_build_fault_attr(sbi, 0, arg);
+			if (f2fs_build_fault_attr(sbi, 0, arg))
+				return -EINVAL;
 			set_opt(sbi, FAULT_INJECTION);
 			break;
 #else
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 906d2af2d849..180a12cdca02 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -484,10 +484,16 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 	if (ret < 0)
 		return ret;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-	if (a->struct_type == FAULT_INFO_TYPE && t >= BIT(FAULT_MAX))
-		return -EINVAL;
-	if (a->struct_type == FAULT_INFO_RATE && t >= UINT_MAX)
-		return -EINVAL;
+	if (a->struct_type == FAULT_INFO_TYPE) {
+		if (f2fs_build_fault_attr(sbi, 0, t))
+			return -EINVAL;
+		return count;
+	}
+	if (a->struct_type == FAULT_INFO_RATE) {
+		if (f2fs_build_fault_attr(sbi, t, 0))
+			return -EINVAL;
+		return count;
+	}
 #endif
 	if (a->struct_type == RESERVED_BLOCKS) {
 		spin_lock(&sbi->stat_lock);
-- 
2.43.0