From: Zhang Yuwei <zhangyuwei20@huawei.com> mainline inclusion from mainline-v6.15-rc1 commit b5799dd77054c1ec49b0088b006c9908e256843b category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC1QOQ CVE: CVE-2024-58094 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Added a check for "read-only" mode in the `jfs_truncate_nolock` function to avoid errors related to writing to a read-only filesystem. Call stack: block_write_begin() { jfs_write_failed() { jfs_truncate() { jfs_truncate_nolock() { txEnd() { ... log = JFS_SBI(tblk->sb)->log; // (log == NULL) If the `isReadOnly(ip)` condition is triggered in `jfs_truncate_nolock`, the function execution will stop, and no further data modification will occur. Instead, the `xtTruncate` function will be called with the "COMMIT_WMAP" flag, preventing modifications in "read-only" mode. Signed-off-by: Zhang Yuwei <zhangyuwei20@huawei.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+4e89b5368baba8324e07@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=4e89b5368baba8324e07 Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> --- fs/jfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c index 68779cc3609a..5a60ba8c021e 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -381,7 +381,7 @@ void jfs_truncate_nolock(struct inode *ip, loff_t length) ASSERT(length >= 0); - if (test_cflag(COMMIT_Nolink, ip)) { + if (test_cflag(COMMIT_Nolink, ip) || isReadOnly(ip)) { xtTruncate(0, ip, length, COMMIT_WMAP); return; } -- 2.22.0