From 1437bce64934eeca3a7e79a28665795f38ca1f7e Mon Sep 17 00:00:00 2001 From: Zhang Yuwei Date: Tue, 29 Apr 2025 17:14:42 +0800 Subject: [PATCH] jfs: add check read-only before truncation in jfs_truncate_nolock() 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/?id=b5799dd77054c1ec49b0088b006c9908e256843b -------------------------------- 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. 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 Signed-off-by: Dave Kleikamp Signed-off-by: Zhang Yuwei --- 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 980aa3300f10..515cd45d0386 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -379,7 +379,7 @@ 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; } -- Gitee