From 33ed0a0567e0abe66ea65e89dad2e35082890fbe Mon Sep 17 00:00:00 2001 From: Jiaming Zhang Date: Mon, 31 Aug 2026 18:54:25 +0800 Subject: [PATCH] gfs2: reject invalid inode sizes A corrupted GFS2 image can store a dinode size that is larger than what VFS i_size can represent. gfs2_dinode_in() reads the on-disk di_size as a u64 and writes it directly into inode->i_size. If the value is larger than S64_MAX, the incore i_size becomes negative. That negative value can bypass the existing stuffed inode size check: inode->i_size > gfs2_max_stuffed_size(ip) Later, gfs2_quotad may try to sync the quota file and unstuff the quota inode. gfs2_unstuffer_folio() reads the negative i_size into an unsigned length and passes it to memcpy(), turning it into a huge copy size and triggering a out-of-bound issue. Reject dinodes whose size exceeds sb->s_maxbytes before storing the value in inode->i_size. Also make the stuffed inode check use the raw on-disk size while it is still unsigned. Fixes: 70376c7ff312 ("gfs2: Always check inode size of inline inodes") Closes: https://lore.kernel.org/lkml/CANypQFaF6bvORKKbRALvEL0k_epFaneFiOQqco4gjdmKVbdURg@mail.gmail.com/ Assisted-by: Codex:gpt-5.5-xhigh Cc: stable@vger.kernel.org Signed-off-by: Jiaming Zhang Signed-off-by: Andreas Gruenbacher --- fs/gfs2/glops.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c index 662d033fd2ca..2597e1cf2315 100644 --- a/fs/gfs2/glops.c +++ b/fs/gfs2/glops.c @@ -393,6 +393,7 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf) umode_t mode = be32_to_cpu(str->di_mode); struct inode *inode = &ip->i_inode; bool is_new = inode_state_read_once(inode) & I_NEW; + u64 size; if (unlikely(ip->i_no_addr != be64_to_cpu(str->di_num.no_addr))) { gfs2_consist_inode(ip); @@ -418,7 +419,12 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf) i_uid_write(inode, be32_to_cpu(str->di_uid)); i_gid_write(inode, be32_to_cpu(str->di_gid)); set_nlink(inode, be32_to_cpu(str->di_nlink)); - i_size_write(inode, be64_to_cpu(str->di_size)); + size = be64_to_cpu(str->di_size); + if (unlikely(size > inode->i_sb->s_maxbytes)) { + gfs2_consist_inode(ip); + return -EIO; + } + i_size_write(inode, size); gfs2_set_inode_blocks(inode, be64_to_cpu(str->di_blocks)); atime.tv_sec = be64_to_cpu(str->di_atime); atime.tv_nsec = be32_to_cpu(str->di_atime_nsec); @@ -462,7 +468,7 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf) return -EIO; } - if (gfs2_is_stuffed(ip) && inode->i_size > gfs2_max_stuffed_size(ip)) { + if (gfs2_is_stuffed(ip) && size > gfs2_max_stuffed_size(ip)) { gfs2_consist_inode(ip); return -EIO; }