6.14-stable review patch. If anyone has any objections, please let me know.
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From: Vasiliy Kovalev kovalev@altlinux.org
[ Upstream commit 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 kovalev@altlinux.org Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 07cfdc4405968..60fc92dee24d2 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -369,7 +369,7 @@ 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; }