From bfa4f1a4700c52254ffa81f1d0710f120c64b67c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 3 Sep 2021 14:02:00 +0200 Subject: [PATCH] 4.9-stable patches added patches: ext4-fix-race-writing-to-an-inline_data-file-while-its-xattrs-are-changing.patch --- ...a-file-while-its-xattrs-are-changing.patch | 42 +++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 queue-4.9/ext4-fix-race-writing-to-an-inline_data-file-while-its-xattrs-are-changing.patch diff --git a/queue-4.9/ext4-fix-race-writing-to-an-inline_data-file-while-its-xattrs-are-changing.patch b/queue-4.9/ext4-fix-race-writing-to-an-inline_data-file-while-its-xattrs-are-changing.patch new file mode 100644 index 00000000000..1d4cb6b5291 --- /dev/null +++ b/queue-4.9/ext4-fix-race-writing-to-an-inline_data-file-while-its-xattrs-are-changing.patch @@ -0,0 +1,42 @@ +From a54c4613dac1500b40e4ab55199f7c51f028e848 Mon Sep 17 00:00:00 2001 +From: Theodore Ts'o +Date: Fri, 20 Aug 2021 23:44:17 -0400 +Subject: ext4: fix race writing to an inline_data file while its xattrs are changing + +From: Theodore Ts'o + +commit a54c4613dac1500b40e4ab55199f7c51f028e848 upstream. + +The location of the system.data extended attribute can change whenever +xattr_sem is not taken. So we need to recalculate the i_inline_off +field since it mgiht have changed between ext4_write_begin() and +ext4_write_end(). + +This means that caching i_inline_off is probably not helpful, so in +the long run we should probably get rid of it and shrink the in-memory +ext4 inode slightly, but let's fix the race the simple way for now. + +Cc: stable@kernel.org +Fixes: f19d5870cbf72 ("ext4: add normal write support for inline data") +Reported-by: syzbot+13146364637c7363a7de@syzkaller.appspotmail.com +Signed-off-by: Theodore Ts'o +Signed-off-by: Greg Kroah-Hartman +--- + fs/ext4/inline.c | 6 ++++++ + 1 file changed, 6 insertions(+) + +--- a/fs/ext4/inline.c ++++ b/fs/ext4/inline.c +@@ -747,6 +747,12 @@ int ext4_write_inline_data_end(struct in + ext4_write_lock_xattr(inode, &no_expand); + BUG_ON(!ext4_has_inline_data(inode)); + ++ /* ++ * ei->i_inline_off may have changed since ext4_write_begin() ++ * called ext4_try_to_write_inline_data() ++ */ ++ (void) ext4_find_inline_data_nolock(inode); ++ + kaddr = kmap_atomic(page); + ext4_write_inline_data(inode, &iloc, kaddr, pos, len); + kunmap_atomic(kaddr); -- 2.47.3