In the Linux kernel, the following vulnerability has been resolved: ext4:
fix bug in extents parsing when eh_entries == 0 and eh_depth > 0 When
walking through an inode extents, the ext4_ext_binsearch_idx() function
assumes that the extent header has been previously validated. However,
there are no checks that verify that the number of entries (eh->eh_entries)
is non-zero when depth is > 0. And this will lead to problems because the
EXT_FIRST_INDEX() and EXT_LAST_INDEX() will return garbage and result in
this: [ 135.245946] ------------[ cut here ]------------ [ 135.247579]
kernel BUG at fs/ext4/extents.c:2258! [ 135.249045] invalid opcode: 0000
[#1] PREEMPT SMP [ 135.250320] CPU: 2 PID: 238 Comm: tmp118 Not tainted
5.19.0-rc8+ #4 [ 135.252067] Hardware name: QEMU Standard PC (i440FX +
PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014 [
135.255065] RIP: 0010:ext4_ext_map_blocks+0xc20/0xcb0 [ 135.256475] Code: [
135.261433] RSP: 0018:ffffc900005939f8 EFLAGS: 00010246 [ 135.262847] RAX:
0000000000000024 RBX: ffffc90000593b70 RCX: 0000000000000023 [ 135.264765]
RDX: ffff8880038e5f10 RSI: 0000000000000003 RDI: ffff8880046e922c [
135.266670] RBP: ffff8880046e9348 R08: 0000000000000001 R09:
ffff888002ca580c [ 135.268576] R10: 0000000000002602 R11: 0000000000000000
R12: 0000000000000024 [ 135.270477] R13: 0000000000000000 R14:
0000000000000024 R15: 0000000000000000 [ 135.272394] FS:
00007fdabdc56740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 [
135.274510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 135.276075]
CR2: 00007ffc26bd4f00 CR3: 0000000006261004 CR4: 0000000000170ea0 [
135.277952] Call Trace: [ 135.278635] <TASK> [ 135.279247] ?
preempt_count_add+0x6d/0xa0 [ 135.280358] ?
percpu_counter_add_batch+0x55/0xb0 [ 135.281612] ?
_raw_read_unlock+0x18/0x30 [ 135.282704] ext4_map_blocks+0x294/0x5a0 [
135.283745] ? xa_load+0x6f/0xa0 [ 135.284562]
ext4_mpage_readpages+0x3d6/0x770 [ 135.285646] read_pages+0x67/0x1d0 [
135.286492] ? folio_add_lru+0x51/0x80 [ 135.287441]
page_cache_ra_unbounded+0x124/0x170 [ 135.288510]
filemap_get_pages+0x23d/0x5a0 [ 135.289457] ? path_openat+0xa72/0xdd0 [
135.290332] filemap_read+0xbf/0x300 [ 135.291158] ?
_raw_spin_lock_irqsave+0x17/0x40 [ 135.292192] new_sync_read+0x103/0x170 [
135.293014] vfs_read+0x15d/0x180 [ 135.293745] ksys_read+0xa1/0xe0 [
135.294461] do_syscall_64+0x3c/0x80 [ 135.295284]
entry_SYSCALL_64_after_hwframe+0x46/0xb0 This patch simply adds an extra
check in __ext4_ext_check(), verifying that eh_entries is not 0 when
eh_depth is > 0.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
ubuntu | 18.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 22.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 23.10 | noarch | linux | < any | UNKNOWN |
ubuntu | 24.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 14.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 16.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 22.04 | noarch | linux-aws | < any | UNKNOWN |
git.kernel.org/linus/29a5b8a137ac8eb410cc823653a29ac0e7b7e1b0 (6.0-rc7)
git.kernel.org/stable/c/29a5b8a137ac8eb410cc823653a29ac0e7b7e1b0
git.kernel.org/stable/c/2f5e9de15e4f55fbf56f22d4a2ce406246cc462d
git.kernel.org/stable/c/958b0ee23f5ac106e7cc11472b71aa2ea9a033bc
git.kernel.org/stable/c/bb7eb3ca4b3b0d2c7872cf1a41c30f5e5bd65df0
git.kernel.org/stable/c/be4df018c0be5ebecf1ca510feacc23be415cefc
launchpad.net/bugs/cve/CVE-2022-48631
nvd.nist.gov/vuln/detail/CVE-2022-48631
security-tracker.debian.org/tracker/CVE-2022-48631
www.cve.org/CVERecord?id=CVE-2022-48631