[PATCH 5.7 176/204] fs/minix: set s_maxbytes correctly

Greg Kroah-Hartman
2020-08-20T12:56:06Z

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