kernel/linux.git/fs/isofs, branch v5.15.209

isofs: validate block number from NFS file handle in isofs_export_iget

2026-06-01T15:35:23+00:00

commit 24376458138387fb251e782e624c7776e9826796 upstream. isofs_fh_to_dentry() and isofs_fh_to_parent() pass an attacker- controlled block number (ifid->block or ifid->parent_block) from the NFS file handle to isofs_export_iget(), which only rejects block == 0 before calling isofs_iget() and ultimately sb_bread(). A crafted file handle with fh_len sufficient to pass the check added by commit 0405d4b63d08 ("isofs: Prevent the use of too small fid") can still drive the server to read any in-range block on the backing device as if it were an iso_directory_record. That earlier fix was assigned CVE-2025-37780. sb_bread() on an out-of-range block returns NULL cleanly via the EIO path, so there is no memory-safety violation. For in-range reads of adjacent-partition data on the same block device, the unrelated bytes end up in iso_inode_info fields that reach the NFS client as dentry metadata. The deployment surface (isofs exported over NFS from loop-mounted images) is narrow and requires an authenticated NFS peer, but the malformed-file-handle class is reportable as hardening next to the existing CVE-2025-37780 fix. Reject block >= ISOFS_SB(sb)->s_nzones in isofs_export_iget() so the check covers both isofs_fh_to_dentry() and isofs_fh_to_parent() call sites with a single line. Fixes: 0405d4b63d08 ("isofs: Prevent the use of too small fid") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260419212155.2169382-3-michael.bommarito@gmail.com Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

isofs: validate Rock Ridge CE continuation extent against volume size

2026-06-01T15:35:23+00:00

commit a36d990f591320e9dd379ab30063ebfe91d47e1f upstream. 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 Link: https://patch.msgid.link/20260419212155.2169382-2-michael.bommarito@gmail.com Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

isofs: Verify inode mode when loading from disk

2025-08-28T14:23:59+00:00

commit 0a9e7405131380b57e155f10242b2e25d2e51852 upstream. Verify that the inode mode is sane when loading it from the disk to avoid complaints from VFS about setting up invalid inodes. Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com CC: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/20250709095545.31062-2-jack@suse.cz Acked-by: Christian Brauner Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

isofs: Prevent the use of too small fid

2025-05-02T05:44:13+00:00

commit 0405d4b63d082861f4eaff9d39c78ee9dc34f845 upstream. syzbot reported a slab-out-of-bounds Read in isofs_fh_to_parent. [1] The handle_bytes value passed in by the reproducing program is equal to 12. In handle_to_path(), only 12 bytes of memory are allocated for the structure file_handle->f_handle member, which causes an out-of-bounds access when accessing the member parent_block of the structure isofs_fid in isofs, because accessing parent_block requires at least 16 bytes of f_handle. Here, fh_len is used to indirectly confirm that the value of handle_bytes is greater than 3 before accessing parent_block. [1] BUG: KASAN: slab-out-of-bounds in isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183 Read of size 4 at addr ffff0000cc030d94 by task syz-executor215/6466 CPU: 1 UID: 0 PID: 6466 Comm: syz-executor215 Not tainted 6.14.0-rc7-syzkaller-ga2392f333575 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x198/0x550 mm/kasan/report.c:521 kasan_report+0xd8/0x138 mm/kasan/report.c:634 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380 isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183 exportfs_decode_fh_raw+0x2dc/0x608 fs/exportfs/expfs.c:523 do_handle_to_path+0xa0/0x198 fs/fhandle.c:257 handle_to_path fs/fhandle.c:385 [inline] do_handle_open+0x8cc/0xb8c fs/fhandle.c:403 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline] __se_sys_open_by_handle_at fs/fhandle.c:434 [inline] __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Allocated by task 6466: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_noprof+0x32c/0x54c mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] handle_to_path fs/fhandle.c:357 [inline] do_handle_open+0x5a4/0xb8c fs/fhandle.c:403 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline] __se_sys_open_by_handle_at fs/fhandle.c:434 [inline] __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Reported-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4d7cd7dd0ce1aa8d5c65 Tested-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com CC: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Edward Adam Davis Signed-off-by: Jan Kara Link: https://patch.msgid.link/tencent_9C8CB8A7E7C6C512C7065DC98B6EDF6EC606@qq.com Signed-off-by: Greg Kroah-Hartman

isofs: fix KMSAN uninit-value bug in do_isofs_readdir()

2025-04-10T12:32:01+00:00

[ Upstream commit 81a82e8f33880793029cd6f8a766fb13b737e6a7 ] In do_isofs_readdir() when assigning the variable "struct iso_directory_record *de" the b_data field of the buffer_head is accessed and an offset is added to it, the size of b_data is 2048 and the offset size is 2047, meaning "de = (struct iso_directory_record *) (bh->b_data + offset);" yields the final byte of the 2048 sized b_data block. The first byte of the directory record (de_len) is then read and found to be 31, meaning the directory record size is 31 bytes long. The directory record is defined by the structure: struct iso_directory_record { __u8 length; // 1 byte __u8 ext_attr_length; // 1 byte __u8 extent[8]; // 8 bytes __u8 size[8]; // 8 bytes __u8 date[7]; // 7 bytes __u8 flags; // 1 byte __u8 file_unit_size; // 1 byte __u8 interleave; // 1 byte __u8 volume_sequence_number[4]; // 4 bytes __u8 name_len; // 1 byte char name[]; // variable size } __attribute__((packed)); The fixed portion of this structure occupies 33 bytes. Therefore, a valid directory record must be at least 33 bytes long (even without considering the variable-length name field). Since de_len is only 31, it is insufficient to contain the complete fixed header. The code later hits the following sanity check that compares de_len against the sum of de->name_len and sizeof(struct iso_directory_record): if (de_len < de->name_len[0] + sizeof(struct iso_directory_record)) { ... } Since the fixed portion of the structure is 33 bytes (up to and including name_len member), a valid record should have de_len of at least 33 bytes; here, however, de_len is too short, and the field de->name_len (located at offset 32) is accessed even though it lies beyond the available 31 bytes. This access on the corrupted isofs data triggers a KASAN uninitialized memory warning. The fix would be to first verify that de_len is at least sizeof(struct iso_directory_record) before accessing any fields like de->name_len. Reported-by: syzbot Tested-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=812641c6c3d7586a1613 Fixes: 2deb1acc653c ("isofs: fix access to unallocated memory when reading corrupted filesystem") Signed-off-by: Qasim Ijaz Signed-off-by: Jan Kara Link: https://patch.msgid.link/20250211195900.42406-1-qasdev00@gmail.com Signed-off-by: Sasha Levin

isofs: handle CDs with bad root inode but good Joliet root directory

2024-04-13T11:01:44+00:00

[ Upstream commit 4243bf80c79211a8ca2795401add9c4a3b1d37ca ] I have a CD copy of the original Tom Clancy's Ghost Recon game from 2001. The disc mounts without error on Windows, but on Linux mounting fails with the message "isofs_fill_super: get root inode failed". The error originates in isofs_read_inode, which returns -EIO because de_len is 0. The superblock on this disc appears to be intentionally corrupt as a form of copy protection. When the root inode is unusable, instead of giving up immediately, try to continue with the Joliet file table. This fixes the Ghost Recon CD and probably other copy-protected CDs too. Signed-off-by: Alex Henrie Signed-off-by: Jan Kara Message-Id: <20240208022134.451490-1-alexhenrie24@gmail.com> Signed-off-by: Sasha Levin

isofs: Fix out of bound access for corrupted isofs image

2021-11-12T14:05:50+00:00

commit e96a1866b40570b5950cda8602c2819189c62a48 upstream. When isofs image is suitably corrupted isofs_read_inode() can read data beyond the end of buffer. Sanity-check the directory entry length before using it. Reported-and-tested-by: syzbot+6fc7fb214625d82af7d1@syzkaller.appspotmail.com CC: stable@vger.kernel.org Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

isofs: joliet: Fix iocharset=utf8 mount option

2021-08-12T14:07:14+00:00

Currently iocharset=utf8 mount option is broken. To use UTF-8 as iocharset, it is required to use utf8 mount option. Fix iocharset=utf8 mount option to use be equivalent to the utf8 mount option. If UTF-8 as iocharset is used then s_nls_iocharset is set to NULL. So simplify code around, remove s_utf8 field as to distinguish between UTF-8 and non-UTF-8 it is needed just to check if s_nls_iocharset is set to NULL or not. Link: https://lore.kernel.org/r/20210808162453.1653-5-pali@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Jan Kara

isofs: remove redundant continue statement

2021-06-17T15:11:42+00:00

The continue statement in the while-loop has no effect, remove it. Addresses-Coverity: ("Continue has no effect") Link: https://lore.kernel.org/r/20210617120837.11994-1-colin.king@canonical.com Signed-off-by: Colin Ian King Signed-off-by: Jan Kara

isofs: fix fall-through warnings for Clang

2021-05-07T02:24:13+00:00

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of just letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Link: https://lkml.kernel.org/r/5b7caa73958588065fabc59032c340179b409ef5.1605896059.git.gustavoars@kernel.org Signed-off-by: Gustavo A. R. Silva Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds