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| author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2018-08-21 21:59:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-22 10:52:50 -0700 |
| commit | 0afa9626667c3659ef8bd82d42a11e39fedf235c (patch) | |
| tree | 9b5c96147d7eb18dc6d6b148e2f02c76b8ef9053 /fs/fat/fatent.c | |
| parent | f663b5b38fffeb31841f8bfaf0ef87a445b0ffee (diff) | |
| download | linux-stable-0afa9626667c3659ef8bd82d42a11e39fedf235c.tar.gz linux-stable-0afa9626667c3659ef8bd82d42a11e39fedf235c.tar.bz2 linux-stable-0afa9626667c3659ef8bd82d42a11e39fedf235c.zip | |
fat: validate ->i_start before using
On corrupted FATfs may have invalid ->i_start. To handle it, this checks
->i_start before using, and return proper error code.
Link: http://lkml.kernel.org/r/87o9f8y1t5.fsf_-_@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Tested-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fat/fatent.c')
| -rw-r--r-- | fs/fat/fatent.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c index 25d43a5e8a4d..defc2168de91 100644 --- a/fs/fat/fatent.c +++ b/fs/fat/fatent.c @@ -24,7 +24,7 @@ static void fat12_ent_blocknr(struct super_block *sb, int entry, { struct msdos_sb_info *sbi = MSDOS_SB(sb); int bytes = entry + (entry >> 1); - WARN_ON(entry < FAT_START_ENT || sbi->max_cluster <= entry); + WARN_ON(!fat_valid_entry(sbi, entry)); *offset = bytes & (sb->s_blocksize - 1); *blocknr = sbi->fat_start + (bytes >> sb->s_blocksize_bits); } @@ -34,7 +34,7 @@ static void fat_ent_blocknr(struct super_block *sb, int entry, { struct msdos_sb_info *sbi = MSDOS_SB(sb); int bytes = (entry << sbi->fatent_shift); - WARN_ON(entry < FAT_START_ENT || sbi->max_cluster <= entry); + WARN_ON(!fat_valid_entry(sbi, entry)); *offset = bytes & (sb->s_blocksize - 1); *blocknr = sbi->fat_start + (bytes >> sb->s_blocksize_bits); } @@ -354,7 +354,7 @@ int fat_ent_read(struct inode *inode, struct fat_entry *fatent, int entry) int err, offset; sector_t blocknr; - if (entry < FAT_START_ENT || sbi->max_cluster <= entry) { + if (!fat_valid_entry(sbi, entry)) { fatent_brelse(fatent); fat_fs_error(sb, "invalid access to FAT (entry 0x%08x)", entry); return -EIO; |