Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
[PATCH] protect ext3 ioctl modifying append_only, immutable, etc. with i_mutex
All modifications of ->i_flags in inodes that might be visible to
somebody else must be under ->i_mutex. That patch fixes ext3 ioctl()
setting S_APPEND and friends.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
authored by
Al Viro
and committed by
Linus Torvalds
a090d913
6ad0013b
+14
-4
+14
-4
fs/ext3/ioctl.c
+14
-4
fs/ext3/ioctl.c
···
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if (!S_ISDIR(inode->i_mode))
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flags &= ~EXT3_DIRSYNC_FL;
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+
mutex_lock(&inode->i_mutex);
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oldflags = ei->i_flags;
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/* The JOURNAL_DATA flag is modifiable only by root */
···
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* This test looks nicer. Thanks to Pauline Middelink
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*/
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if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
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-
if (!capable(CAP_LINUX_IMMUTABLE))
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+
if (!capable(CAP_LINUX_IMMUTABLE)) {
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+
mutex_unlock(&inode->i_mutex);
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return -EPERM;
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+
}
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}
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/*
···
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* the relevant capability.
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*/
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if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
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-
if (!capable(CAP_SYS_RESOURCE))
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+
if (!capable(CAP_SYS_RESOURCE)) {
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+
mutex_unlock(&inode->i_mutex);
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return -EPERM;
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+
}
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}
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handle = ext3_journal_start(inode, 1);
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-
if (IS_ERR(handle))
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+
if (IS_ERR(handle)) {
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+
mutex_unlock(&inode->i_mutex);
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return PTR_ERR(handle);
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+
}
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if (IS_SYNC(inode))
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handle->h_sync = 1;
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err = ext3_reserve_inode_write(handle, inode, &iloc);
···
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err = ext3_mark_iloc_dirty(handle, inode, &iloc);
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flags_err:
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ext3_journal_stop(handle);
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-
if (err)
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+
if (err) {
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+
mutex_unlock(&inode->i_mutex);
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return err;
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+
}
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if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
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err = ext3_change_inode_journal_flag(inode, jflag);
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+
mutex_unlock(&inode->i_mutex);
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return err;
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}
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case EXT3_IOC_GETVERSION: