This is a note to let you know that I've just added the patch titled jfs: Fix fortify moan in symlink to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: jfs-fix-fortify-moan-in-symlink.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8819a11f3978f666d2707f38b81e0803ddc0beed Author: Dr. David Alan Gilbert <linux@xxxxxxxxxxx> Date: Sat Oct 22 21:39:14 2022 +0100 jfs: Fix fortify moan in symlink [ Upstream commit ebe060369f8d6e4588b115f252bebf5ba4d64350 ] JFS has in jfs_incore.h: /* _inline may overflow into _inline_ea when needed */ /* _inline_ea may overlay the last part of * file._xtroot if maxentry = XTROOTINITSLOT */ union { struct { /* 128: inline symlink */ unchar _inline[128]; /* 128: inline extended attr */ unchar _inline_ea[128]; }; unchar _inline_all[256]; and currently the symlink code copies into _inline; if this is larger than 128 bytes it triggers a fortify warning of the form: memcpy: detected field-spanning write (size 132) of single field "ip->i_link" at fs/jfs/namei.c:950 (size 18446744073709551615) when it's actually OK. Copy it into _inline_all instead. Reported-by: syzbot+5fc38b2ddbbca7f5c680@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dr. David Alan Gilbert <linux@xxxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c index 9db4f5789c0e..4fbbf88435e6 100644 --- a/fs/jfs/namei.c +++ b/fs/jfs/namei.c @@ -946,7 +946,7 @@ static int jfs_symlink(struct user_namespace *mnt_userns, struct inode *dip, if (ssize <= IDATASIZE) { ip->i_op = &jfs_fast_symlink_inode_operations; - ip->i_link = JFS_IP(ip)->i_inline; + ip->i_link = JFS_IP(ip)->i_inline_all; memcpy(ip->i_link, name, ssize); ip->i_size = ssize - 1;