The patch titled
Subject: nilfs2: fix missing error check for sb_set_blocksize call
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
nilfs2-fix-missing-error-check-for-sb_set_blocksize-call.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-fix-missing-error-check-for-sb_set_blocksize-call.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Subject: nilfs2: fix missing error check for sb_set_blocksize call
Date: Wed, 29 Nov 2023 23:15:47 +0900
When mounting a filesystem image with a block size larger than the page
size, nilfs2 repeatedly outputs long error messages with stack traces to
the kernel log, such as the following:
getblk(): invalid block size 8192 requested
logical block size: 512
...
Call Trace:
dump_stack_lvl+0x92/0xd4
dump_stack+0xd/0x10
bdev_getblk+0x33a/0x354
__breadahead+0x11/0x80
nilfs_search_super_root+0xe2/0x704 [nilfs2]
load_nilfs+0x72/0x504 [nilfs2]
nilfs_mount+0x30f/0x518 [nilfs2]
legacy_get_tree+0x1b/0x40
vfs_get_tree+0x18/0xc4
path_mount+0x786/0xa88
__ia32_sys_mount+0x147/0x1a8
__do_fast_syscall_32+0x56/0xc8
do_fast_syscall_32+0x29/0x58
do_SYSENTER_32+0x15/0x18
entry_SYSENTER_32+0x98/0xf1
...
This overloads the system logger. And to make matters worse, it sometimes
crashes the kernel with a memory access violation.
This is because the return value of the sb_set_blocksize() call, which
should be checked for errors, is not checked.
The latter issue is due to out-of-buffer memory being accessed based on a
large block size that caused sb_set_blocksize() to fail for buffers read
with the initial minimum block size that remained unupdated in the
super_block structure.
Since nilfs2 mkfs tool does not accept block sizes larger than the system
page size, this has been overlooked. However, it is possible to create
this situation by intentionally modifying the tool or by passing a
filesystem image created on a system with a large page size to a system
with a smaller page size and mounting it.
Fix this issue by inserting the expected error handling for the call to
sb_set_blocksize().
Link: https://lkml.kernel.org/r/20231129141547.4726-1-konishi.ryusuke@xxxxxxxxx
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Tested-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/nilfs2/the_nilfs.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/nilfs2/the_nilfs.c~nilfs2-fix-missing-error-check-for-sb_set_blocksize-call
+++ a/fs/nilfs2/the_nilfs.c
@@ -716,7 +716,11 @@ int init_nilfs(struct the_nilfs *nilfs,
goto failed_sbh;
}
nilfs_release_super_block(nilfs);
- sb_set_blocksize(sb, blocksize);
+ if (!sb_set_blocksize(sb, blocksize)) {
+ nilfs_err(sb, "bad blocksize %d", blocksize);
+ err = -EINVAL;
+ goto out;
+ }
err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
if (err)
_
Patches currently in -mm which might be from konishi.ryusuke@xxxxxxxxx are
nilfs2-fix-missing-error-check-for-sb_set_blocksize-call.patch
nilfs2-move-page-release-outside-of-nilfs_delete_entry-and-nilfs_set_link.patch
nilfs2-eliminate-staggered-calls-to-kunmap-in-nilfs_rename.patch
