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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Eric Biggers <ebiggers@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Qiujun Huang <anenbupt@gmail.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.8 206/232] fs/minix: set s_maxbytes correctly
Date:   Thu, 20 Aug 2020 11:20:57 +0200
Message-Id: <20200820091622.789069368@linuxfoundation.org>
In-Reply-To: <20200820091612.692383444@linuxfoundation.org>
References: <20200820091612.692383444@linuxfoundation.org>
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From: Eric Biggers <ebiggers@google.com>

[ Upstream commit 32ac86efff91a3e4ef8c3d1cadd4559e23c8e73a ]

The minix filesystem leaves super_block::s_maxbytes at MAX_NON_LFS rather
than setting it to the actual filesystem-specific limit.  This is broken
because it means userspace doesn't see the standard behavior like getting
EFBIG and SIGXFSZ when exceeding the maximum file size.

Fix this by setting s_maxbytes correctly.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qiujun Huang <anenbupt@gmail.com>
Link: http://lkml.kernel.org/r/20200628060846.682158-5-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/minix/inode.c    | 12 +++++++-----
 fs/minix/itree_v1.c |  2 +-
 fs/minix/itree_v2.c |  3 +--
 fs/minix/minix.h    |  1 -
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 0dd929346f3f3..7b09a9158e401 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -150,8 +150,10 @@ static int minix_remount (struct super_block * sb, int * flags, char * data)
 	return 0;
 }
 
-static bool minix_check_superblock(struct minix_sb_info *sbi)
+static bool minix_check_superblock(struct super_block *sb)
 {
+	struct minix_sb_info *sbi = minix_sb(sb);
+
 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
 		return false;
 
@@ -161,7 +163,7 @@ static bool minix_check_superblock(struct minix_sb_info *sbi)
 	 * of indirect blocks which places the limit well above U32_MAX.
 	 */
 	if (sbi->s_version == MINIX_V1 &&
-	    sbi->s_max_size > (7 + 512 + 512*512) * BLOCK_SIZE)
+	    sb->s_maxbytes > (7 + 512 + 512*512) * BLOCK_SIZE)
 		return false;
 
 	return true;
@@ -202,7 +204,7 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
 	sbi->s_firstdatazone = ms->s_firstdatazone;
 	sbi->s_log_zone_size = ms->s_log_zone_size;
-	sbi->s_max_size = ms->s_max_size;
+	s->s_maxbytes = ms->s_max_size;
 	s->s_magic = ms->s_magic;
 	if (s->s_magic == MINIX_SUPER_MAGIC) {
 		sbi->s_version = MINIX_V1;
@@ -233,7 +235,7 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
 		sbi->s_firstdatazone = m3s->s_firstdatazone;
 		sbi->s_log_zone_size = m3s->s_log_zone_size;
-		sbi->s_max_size = m3s->s_max_size;
+		s->s_maxbytes = m3s->s_max_size;
 		sbi->s_ninodes = m3s->s_ninodes;
 		sbi->s_nzones = m3s->s_zones;
 		sbi->s_dirsize = 64;
@@ -245,7 +247,7 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
 	} else
 		goto out_no_fs;
 
-	if (!minix_check_superblock(sbi))
+	if (!minix_check_superblock(s))
 		goto out_illegal_sb;
 
 	/*
diff --git a/fs/minix/itree_v1.c b/fs/minix/itree_v1.c
index 046cc96ee7adb..c0d418209ead1 100644
--- a/fs/minix/itree_v1.c
+++ b/fs/minix/itree_v1.c
@@ -29,7 +29,7 @@ static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
 	if (block < 0) {
 		printk("MINIX-fs: block_to_path: block %ld < 0 on dev %pg\n",
 			block, inode->i_sb->s_bdev);
-	} else if (block >= (minix_sb(inode->i_sb)->s_max_size/BLOCK_SIZE)) {
+	} else if (block >= inode->i_sb->s_maxbytes/BLOCK_SIZE) {
 		if (printk_ratelimit())
 			printk("MINIX-fs: block_to_path: "
 			       "block %ld too big on dev %pg\n",
diff --git a/fs/minix/itree_v2.c b/fs/minix/itree_v2.c
index f7fc7eccccccd..ee8af2f9e2828 100644
--- a/fs/minix/itree_v2.c
+++ b/fs/minix/itree_v2.c
@@ -32,8 +32,7 @@ static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
 	if (block < 0) {
 		printk("MINIX-fs: block_to_path: block %ld < 0 on dev %pg\n",
 			block, sb->s_bdev);
-	} else if ((u64)block * (u64)sb->s_blocksize >=
-			minix_sb(sb)->s_max_size) {
+	} else if ((u64)block * (u64)sb->s_blocksize >= sb->s_maxbytes) {
 		if (printk_ratelimit())
 			printk("MINIX-fs: block_to_path: "
 			       "block %ld too big on dev %pg\n",
diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index df081e8afcc3c..168d45d3de73e 100644
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -32,7 +32,6 @@ struct minix_sb_info {
 	unsigned long s_zmap_blocks;
 	unsigned long s_firstdatazone;
 	unsigned long s_log_zone_size;
-	unsigned long s_max_size;
 	int s_dirsize;
 	int s_namelen;
 	struct buffer_head ** s_imap;
-- 
2.25.1