Cc ntfs3:
Maybe it's a problem like this:
do_new_mount
fs_context_for_mount
alloc_fs_context
ntfs_init_fs_context
sbi = kzalloc(sizeof(struct ntfs_sb_info), GFP_NOFS);
fc->s_fs_info = sbi;
vfs_get_tree
ntfs_fs_get_tree
get_tree_bdev
blkdev_get_by_path // return error and sbi->sb will be NULL
put_fs_context
ntfs_fs_free
put_ntfs
ntfs_update_mftmirr
struct super_block *sb = sbi->sb; // NULL
u32 blocksize = sb->s_blocksize; // BOOM
It's actually a ntfs3 bug which may be introduced by:
610f8f5a7baf fs/ntfs3: Use new api for mounting
On 2021/11/26 2:03, Linus Torvalds wrote:
On Thu, Nov 25, 2021 at 6:08 AM kernel test robot <oliver.sang@xxxxxxxxx> wrote:
FYI, we noticed the following commit (built with clang-14):
commit: 0858d7da8a09e440fb192a0239d20249a2d16af8 ("ramfs: fix mount source show for ramfs")
Funky. That commit seems to have nothing to do with the oops:
[ 806.257788][ T204] /dev/root: Can't open blockdev
[ 806.259101][ T204] general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN
[ 806.263082][ T204] KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Not a very helpful error message,a nd the KASAN comment makes little sense, but
[ 806.267540][ T204] RIP: 0010:ntfs_update_mftmirr (kbuild/src/consumer/fs/ntfs3/fsntfs.c:834)
That's
u32 blocksize = sb->s_blocksize;
and presumably with KASAN you end up getting hat odd 0xdffffc0000000003 thing.
Anyway, looks like sb is NULL, and the code is
int ntfs_update_mftmirr(struct ntfs_sb_info *sbi, int wait)
{
int err;
struct super_block *sb = sbi->sb;
u32 blocksize = sb->s_blocksize;
sector_t block1, block2;
although I have no idea how sbi->sb could be NULL.
Konstantin? See
https://lore.kernel.org/lkml/20211125140816.GC3109@xsang-OptiPlex-9020/
for the full thing.
Linus
.
