5.5

CVE-2024-50212

lib: alloc_tag_module_unload must wait for pending kfree_rcu calls

In the Linux kernel, the following vulnerability has been resolved:

lib: alloc_tag_module_unload must wait for pending kfree_rcu calls

Ben Greear reports following splat:
 ------------[ cut here ]------------
 net/netfilter/nf_nat_core.c:1114 module nf_nat func:nf_nat_register_fn has 256 allocated at module unload
 WARNING: CPU: 1 PID: 10421 at lib/alloc_tag.c:168 alloc_tag_module_unload+0x22b/0x3f0
 Modules linked in: nf_nat(-) btrfs ufs qnx4 hfsplus hfs minix vfat msdos fat
...
 Hardware name: Default string Default string/SKYBAY, BIOS 5.12 08/04/2020
 RIP: 0010:alloc_tag_module_unload+0x22b/0x3f0
  codetag_unload_module+0x19b/0x2a0
  ? codetag_load_module+0x80/0x80

nf_nat module exit calls kfree_rcu on those addresses, but the free
operation is likely still pending by the time alloc_tag checks for leaks.

Wait for outstanding kfree_rcu operations to complete before checking
resolves this warning.

Reproducer:
unshare -n iptables-nft -t nat -A PREROUTING -p tcp
grep nf_nat /proc/allocinfo # will list 4 allocations
rmmod nft_chain_nat
rmmod nf_nat                # will WARN.

[akpm@linux-foundation.org: add comment]
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 6.10 < 6.11.7
Linux ≫ Linux Kernel Version6.12 Updaterc1
Linux ≫ Linux Kernel Version6.12 Updaterc2
Linux ≫ Linux Kernel Version6.12 Updaterc3
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.1% 0.284
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-401 Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.