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 0176e69743ecc02961f2ae1ea42439cd2bf9ed58 ]
Added a read-only check before calling `txBeginAnon` in `extAlloc` and `extRecord`. This prevents modification attempts on a read-only mounted filesystem, avoiding potential errors or crashes.
Call trace: txBeginAnon+0xac/0x154 extAlloc+0xe8/0xdec fs/jfs/jfs_extent.c:78 jfs_get_block+0x340/0xb98 fs/jfs/inode.c:248 __block_write_begin_int+0x580/0x166c fs/buffer.c:2128 __block_write_begin fs/buffer.c:2177 [inline] block_write_begin+0x98/0x11c fs/buffer.c:2236 jfs_write_begin+0x44/0x88 fs/jfs/inode.c:299
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/jfs_extent.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/fs/jfs/jfs_extent.c b/fs/jfs/jfs_extent.c index 63d21822d309b..46529bcc8297e 100644 --- a/fs/jfs/jfs_extent.c +++ b/fs/jfs/jfs_extent.c @@ -74,6 +74,11 @@ extAlloc(struct inode *ip, s64 xlen, s64 pno, xad_t * xp, bool abnr) int rc; int xflag;
+ if (isReadOnly(ip)) { + jfs_error(ip->i_sb, "read-only filesystem\n"); + return -EIO; + } + /* This blocks if we are low on resources */ txBeginAnon(ip->i_sb);
@@ -253,6 +258,11 @@ int extRecord(struct inode *ip, xad_t * xp) { int rc;
+ if (isReadOnly(ip)) { + jfs_error(ip->i_sb, "read-only filesystem\n"); + return -EIO; + } + txBeginAnon(ip->i_sb);
mutex_lock(&JFS_IP(ip)->commit_mutex);