416baaa9-dc9f-4396-8d5f-8c081fb06d67CVE-2024-26645CVE-2024-26645
In the Linux kernel, the following vulnerability has been resolved:
tracing: Ensure visibility when inserting an element into tracing_map
Running the following two commands in parallel on a multi-processor
AArch64 machine can sporadically produce an unexpected warning about
duplicate histogram entries:
$ while true; do
echo hist:key=id.syscall:val=hitcount >
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
sleep 0.001
done
$ stress-ng --sysbadaddr $(nproc)
The warning looks as follows:
[ 2911.172474] ------------[ cut here ]------------
[ 2911.173111] Duplicates detected: 1
[ 2911.173574] WARNING: CPU: 2 PID: 12247 at kernel/trace/tracing_map.c:983 tracing_map_sort_entries+0x3e0/0x408
[ 2911.174702] Modules linked in: iscsi_ibft(E) iscsi_boot_sysfs(E) rfkill(E) af_packet(E) nls_iso8859_1(E) nls_cp437(E) vfat(E) fat(E) ena(E) tiny_power_button(E) qemu_fw_cfg(E) button(E) fuse(E) efi_pstore(E) ip_tables(E) x_tables(E) xfs(E) libcrc32c(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) polyval_ce(E) polyval_generic(E) ghash_ce(E) gf128mul(E) sm4_ce_gcm(E) sm4_ce_ccm(E) sm4_ce(E) sm4_ce_cipher(E) sm4(E) sm3_ce(E) sm3(E) sha3_ce(E) sha512_ce(E) sha512_arm64(E) sha2_ce(E) sha256_arm64(E) nvme(E) sha1_ce(E) nvme_core(E) nvme_auth(E) t10_pi(E) sg(E) scsi_mod(E) scsi_common(E) efivarfs(E)
[ 2911.174738] Unloaded tainted modules: cppc_cpufreq(E):1
[ 2911.180985] CPU: 2 PID: 12247 Comm: cat Kdump: loaded Tainted: G E 6.7.0-default #2 1b58bbb22c97e4399dc09f92d309344f69c44a01
[ 2911.182398] Hardware name: Amazon EC2 c7g.8xlarge/, BIOS 1.0 11/1/2018
[ 2911.183208] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=–)
[ 2911.184038] pc : tracing_map_sort_entries+0x3e0/0x408
[ 2911.184667] lr : tracing_map_sort_entries+0x3e0/0x408
[ 2911.185310] sp : ffff8000a1513900
[ 2911.185750] x29: ffff8000a1513900 x28: ffff0003f272fe80 x27: 0000000000000001
[ 2911.186600] x26: ffff0003f272fe80 x25: 0000000000000030 x24: 0000000000000008
[ 2911.187458] x23: ffff0003c5788000 x22: ffff0003c16710c8 x21: ffff80008017f180
[ 2911.188310] x20: ffff80008017f000 x19: ffff80008017f180 x18: ffffffffffffffff
[ 2911.189160] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000a15134b8
[ 2911.190015] x14: 0000000000000000 x13: 205d373432323154 x12: 5b5d313131333731
[ 2911.190844] x11: 00000000fffeffff x10: 00000000fffeffff x9 : ffffd1b78274a13c
[ 2911.191716] x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 000000000057ffa8
[ 2911.192554] x5 : ffff0012f6c24ec0 x4 : 0000000000000000 x3 : ffff2e5b72b5d000
[ 2911.193404] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0003ff254480
[ 2911.194259] Call trace:
[ 2911.194626] tracing_map_sort_entries+0x3e0/0x408
[ 2911.195220] hist_show+0x124/0x800
[ 2911.195692] seq_read_iter+0x1d4/0x4e8
[ 2911.196193] seq_read+0xe8/0x138
[ 2911.196638] vfs_read+0xc8/0x300
[ 2911.197078] ksys_read+0x70/0x108
[ 2911.197534] __arm64_sys_read+0x24/0x38
[ 2911.198046] invoke_syscall+0x78/0x108
[ 2911.198553] el0_svc_common.constprop.0+0xd0/0xf8
[ 2911.199157] do_el0_svc+0x28/0x40
[ 2911.199613] el0_svc+0x40/0x178
[ 2911.200048] el0t_64_sync_handler+0x13c/0x158
[ 2911.200621] el0t_64_sync+0x1a8/0x1b0
[ 2911.201115] —[ end trace 0000000000000000 ]—
The problem appears to be caused by CPU reordering of writes issued from
__tracing_map_insert().
The check for the presence of an element with a given key in this
function is:
val = READ_ONCE(entry->val);
if (val && keys_match(key, val->key, map->key_size)) …
The write of a new entry is:
elt = get_free_elt(map);
memcpy(elt->key, key, map->key_size);
entry->val = elt;
The “memcpy(elt->key, key, map->key_size);” and “entry->val = elt;”
stores may become visible in the reversed order on another CPU. This
second CPU might then incorrectly determine that a new key doesn’t match
an already present val->key and subse
—truncated—
Affected configurations
| Vendor | Product | Version | CPE |
|---|---|---|---|
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
CNA Affected
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/trace/tracing_map.c"
],
"versions": [
{
"version": "c193707dde77",
"lessThan": "5022b331c041",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "dad9b28f675e",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "ef70dfa0b1e5",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "aef1cb00856c",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "f4f7e696db02",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "a1eebe76e187",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "bf4aeff7da85",
"status": "affected",
"versionType": "git"
},
{
"version": "c193707dde77",
"lessThan": "2b44760609e9",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/trace/tracing_map.c"
],
"versions": [
{
"version": "4.17",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.17",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.19.307",
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.269",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.210",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.149",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.76",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.15",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.7.3",
"lessThanOrEqual": "6.7.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.8",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]References
git.kernel.org/stable/c/2b44760609e9eaafc9d234a6883d042fc21132a7
git.kernel.org/stable/c/5022b331c041e8c54b9a6a3251579bd1e8c0fc0b
git.kernel.org/stable/c/a1eebe76e187dbe11ca299f8dbb6e45d5b1889e7
git.kernel.org/stable/c/aef1cb00856ccfd614467cfb50b791278992e177
git.kernel.org/stable/c/bf4aeff7da85c3becd39fb73bac94122331c30fb
git.kernel.org/stable/c/dad9b28f675ed99b4dec261db2a397efeb80b74c
git.kernel.org/stable/c/ef70dfa0b1e5084f32635156c9a5c795352ad860
git.kernel.org/stable/c/f4f7e696db0274ff560482cc52eddbf0551d4b7a
lists.debian.org/debian-lts-announce/2024/06/msg00017.html
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