From: Michael Bommarito <michael.bommarito@gmail.com> mainline inclusion from mainline-v7.0 commit a36d990f591320e9dd379ab30063ebfe91d47e1f category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15613 CVE: CVE-2026-46303 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- rock_continue() reads rs->cont_extent verbatim from the Rock Ridge CE record and passes it to sb_bread() without checking that the block number is within the mounted ISO 9660 volume. commit e595447e177b ("[PATCH] rock.c: handle corrupted directories") added cont_offset and cont_size rejection for the CE continuation but did not validate the extent block number itself. commit f54e18f1b831 ("isofs: Fix infinite looping over CE entries") later capped the CE chain length at RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked. With a crafted ISO mounted via udisks2 (desktop optical auto-mount) or via CAP_SYS_ADMIN mount, rs->cont_extent can therefore point at an out-of-range block or at blocks belonging to an adjacent filesystem on the same block device. sb_bread() on an out-of-range block returns NULL cleanly via the block layer EIO path, so there is no memory-safety violation. For in-range reads of adjacent- filesystem data, the CE buffer is parsed as Rock Ridge records and only the text of SL sub-records reaches userspace through readlink(), which makes the info-leak channel narrow and difficult to exploit; still, rejecting the malformed CE outright matches the rejection shape already present in the same function for cont_offset and cont_size. Add an ISOFS_SB(sb)->s_nzones bounds check to rock_continue() next to the existing offset/size rejection, printing the same corrupted-directory-entry notice. Fixes: f54e18f1b831 ("isofs: Fix infinite looping over CE entries") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Link: https://patch.msgid.link/20260419212155.2169382-2-michael.bommarito@gmail.co... Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/isofs/rock.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c index 94ef92fe806c..1efa3ae2f41e 100644 --- a/fs/isofs/rock.c +++ b/fs/isofs/rock.c @@ -101,6 +101,15 @@ static int rock_continue(struct rock_state *rs) goto out; } + if ((unsigned)rs->cont_extent >= ISOFS_SB(rs->inode->i_sb)->s_nzones) { + printk(KERN_NOTICE "rock: corrupted directory entry. " + "extent=%u out of volume (nzones=%lu)\n", + (unsigned)rs->cont_extent, + ISOFS_SB(rs->inode->i_sb)->s_nzones); + ret = -EIO; + goto out; + } + if (rs->cont_extent) { struct buffer_head *bh; -- 2.52.0