ghsa-9r47-mqc5-7vfp
Vulnerability from github
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]
This patch simply adds an extra check in __ext4_ext_check(), verifying that eh_entries is not 0 when eh_depth is > 0.
{
"affected": [],
"aliases": [
"CVE-2022-48631"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-28T13:15:06Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix bug in extents parsing when eh_entries == 0 and eh_depth \u003e 0\n\nWhen walking through an inode extents, the ext4_ext_binsearch_idx() function\nassumes that the extent header has been previously validated. However, there\nare no checks that verify that the number of entries (eh-\u003eeh_entries) is\nnon-zero when depth is \u003e 0. And this will lead to problems because the\nEXT_FIRST_INDEX() and EXT_LAST_INDEX() will return garbage and result in this:\n\n[ 135.245946] ------------[ cut here ]------------\n[ 135.247579] kernel BUG at fs/ext4/extents.c:2258!\n[ 135.249045] invalid opcode: 0000 [#1] PREEMPT SMP\n[ 135.250320] CPU: 2 PID: 238 Comm: tmp118 Not tainted 5.19.0-rc8+ #4\n[ 135.252067] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014\n[ 135.255065] RIP: 0010:ext4_ext_map_blocks+0xc20/0xcb0\n[ 135.256475] Code:\n[ 135.261433] RSP: 0018:ffffc900005939f8 EFLAGS: 00010246\n[ 135.262847] RAX: 0000000000000024 RBX: ffffc90000593b70 RCX: 0000000000000023\n[ 135.264765] RDX: ffff8880038e5f10 RSI: 0000000000000003 RDI: ffff8880046e922c\n[ 135.266670] RBP: ffff8880046e9348 R08: 0000000000000001 R09: ffff888002ca580c\n[ 135.268576] R10: 0000000000002602 R11: 0000000000000000 R12: 0000000000000024\n[ 135.270477] R13: 0000000000000000 R14: 0000000000000024 R15: 0000000000000000\n[ 135.272394] FS: 00007fdabdc56740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000\n[ 135.274510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 135.276075] CR2: 00007ffc26bd4f00 CR3: 0000000006261004 CR4: 0000000000170ea0\n[ 135.277952] Call Trace:\n[ 135.278635] \u003cTASK\u003e\n[ 135.279247] ? preempt_count_add+0x6d/0xa0\n[ 135.280358] ? percpu_counter_add_batch+0x55/0xb0\n[ 135.281612] ? _raw_read_unlock+0x18/0x30\n[ 135.282704] ext4_map_blocks+0x294/0x5a0\n[ 135.283745] ? xa_load+0x6f/0xa0\n[ 135.284562] ext4_mpage_readpages+0x3d6/0x770\n[ 135.285646] read_pages+0x67/0x1d0\n[ 135.286492] ? folio_add_lru+0x51/0x80\n[ 135.287441] page_cache_ra_unbounded+0x124/0x170\n[ 135.288510] filemap_get_pages+0x23d/0x5a0\n[ 135.289457] ? path_openat+0xa72/0xdd0\n[ 135.290332] filemap_read+0xbf/0x300\n[ 135.291158] ? _raw_spin_lock_irqsave+0x17/0x40\n[ 135.292192] new_sync_read+0x103/0x170\n[ 135.293014] vfs_read+0x15d/0x180\n[ 135.293745] ksys_read+0xa1/0xe0\n[ 135.294461] do_syscall_64+0x3c/0x80\n[ 135.295284] entry_SYSCALL_64_after_hwframe+0x46/0xb0\n\nThis patch simply adds an extra check in __ext4_ext_check(), verifying that\neh_entries is not 0 when eh_depth is \u003e 0.",
"id": "GHSA-9r47-mqc5-7vfp",
"modified": "2024-04-28T15:30:28Z",
"published": "2024-04-28T15:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-48631"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/29a5b8a137ac8eb410cc823653a29ac0e7b7e1b0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2f5e9de15e4f55fbf56f22d4a2ce406246cc462d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/958b0ee23f5ac106e7cc11472b71aa2ea9a033bc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bb7eb3ca4b3b0d2c7872cf1a41c30f5e5bd65df0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/be4df018c0be5ebecf1ca510feacc23be415cefc"
}
],
"schema_version": "1.4.0",
"severity": []
}