In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Prevent lock inversion deadlock in map delete elem
syzkaller started using corpuses where a BPF tracing program deletes
elements from a sockmap/sockhash map. Because BPF tracing programs can be
invoked from any interrupt context, locks taken during a map_delete_elem
operation must be hardirq-safe. Otherwise a deadlock due to lock inversion
is possible, as reported by lockdep:
CPU0 CPU1
---- ----
lock(&htab->buckets[i].lock);
local_irq_disable();
lock(&host->lock);
lock(&htab->buckets[i].lock);
<Interrupt>
lock(&host->lock);
Locks in sockmap are hardirq-unsafe by design. We expects elements to be
deleted from sockmap/sockhash only in task (normal) context with interrupts
enabled, or in softirq context.
Detect when map_delete_elem operation is invoked from a context which is
not hardirq-unsafe, that is interrupts are disabled, and bail out with an
error.
Note that map updates are not affected by this issue. BPF verifier does not
allow updating sockmap/sockhash from a BPF tracing program today.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "604326b41a6f",
"lessThan": "f7990498b05a",
"versionType": "git"
},
{
"status": "affected",
"version": "604326b41a6f",
"lessThan": "dd54b48db0c8",
"versionType": "git"
},
{
"status": "affected",
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"lessThan": "d1e73fb19a4c",
"versionType": "git"
},
{
"status": "affected",
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"lessThan": "a44770fed865",
"versionType": "git"
},
{
"status": "affected",
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"lessThan": "668b3074aa14",
"versionType": "git"
},
{
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},
{
"status": "affected",
"version": "604326b41a6f",
"lessThan": "ff9105993240",
"versionType": "git"
}
],
"programFiles": [
"net/core/sock_map.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.20",
"versionType": "custom"
},
{
"status": "unaffected",
"version": "5.4.274",
"versionType": "custom",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.215",
"versionType": "custom",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.154",
"versionType": "custom",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.85",
"versionType": "custom",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.26",
"versionType": "custom",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.8.5",
"versionType": "custom",
"lessThanOrEqual": "6.8.*"
},
{
"status": "unaffected",
"version": "6.9",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/core/sock_map.c"
],
"defaultStatus": "affected"
}
]
git.kernel.org/stable/c/668b3074aa14829e2ac2759799537a93b60fef86
git.kernel.org/stable/c/6af057ccdd8e7619960aca1f0428339f213b31cd
git.kernel.org/stable/c/a44770fed86515eedb5a7c00b787f847ebb134a5
git.kernel.org/stable/c/d1e73fb19a4c872d7a399ad3c66e8ca30e0875ec
git.kernel.org/stable/c/dd54b48db0c822ae7b520bc80751f0a0a173ef75
git.kernel.org/stable/c/f7990498b05ac41f7d6a190dc0418ef1d21bf058
git.kernel.org/stable/c/ff91059932401894e6c86341915615c5eb0eca48
lists.debian.org/debian-lts-announce/2024/06/msg00017.html