cbcvebase.
CVE-2024-53079
published 2024-11-19

CVE-2024-53079: In the Linux kernel, the following vulnerability has been resolved: mm/thp: fix deferred split unqueue naming and locking Recent changes are putting more…

PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.17%
6.7th percentile
In the Linux kernel, the following vulnerability has been resolved: mm/thp: fix deferred split unqueue naming and locking Recent changes are putting more pressure on THP deferred split queues: under load revealing long-standing races, causing list_del corruptions, "Bad page state"s and worse (I keep BUGs in both of those, so usually don't get to see how badly they end up without). The relevant recent changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin, improved swap allocation, and underused THP splitting. Before fixing locking: rename misleading folio_undo_large_rmappable(), which does not undo large_rmappable, to folio_unqueue_deferred_split(), which is what it does. But that and its out-of-line __callee are mm internals of very limited usability: add comment and WARN_ON_ONCEs to check usage; and return a bool to say if a deferred split was unqueued, which can then be used in WARN_ON_ONCEs around safety checks (sparing callers the arcane conditionals in __folio_unqueue_deferred_split()). Just omit the folio_unqueue_deferred_split() from free_unref_folios(), all of whose callers now call it beforehand (and if any forget then bad_page() will tell) - except for its caller put_pages_list(), which itself no longer has any callers (and will be deleted separately). Swapout: mem_cgroup_swapout() has been resetting folio->memcg_data 0 without checking and unqueueing a THP folio from deferred split list; which is unfortunate, since the split_queue_lock depends on the memcg (when memcg is enabled); so swapout has been unqueueing such THPs later, when freeing the folio, using the pgdat's lock instead: potentially corrupting the memcg's list. __remove_mapping() has frozen refcount to 0 here, so no problem with calling folio_unqueue_deferred_split() before resetting memcg_data. That goes back to 5.4 commit 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware"): which included a check on swapcache before adding to deferred queue, but no check

Affected

22 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.11.9-1 (forky)linux 6.11.9-1 (forky)
linuxlinux
linuxlinux>= 87eaceb3faa59b9b4d940ec9554ce251325d83fe < fc4951c3e3358dd82ea508e893695b916c813f17fc4951c3e3358dd82ea508e893695b916c813f17
linuxlinux>= 87eaceb3faa59b9b4d940ec9554ce251325d83fe < afb1352d06b1b6b2cfd1f901c766a430c87078b3afb1352d06b1b6b2cfd1f901c766a430c87078b3
linuxlinux>= 87eaceb3faa59b9b4d940ec9554ce251325d83fe < f8f931bba0f92052cf842b7e30917b1afcc77d5af8f931bba0f92052cf842b7e30917b1afcc77d5a
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.11.9-16.11.9-1
linuxlinux_kernel>= 0 < 6.11.9-16.11.9-1
linuxlinux_kernel>= 0 < 6.8.0-58.606.8.0-58.60
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 5.4 < 6.6.626.6.62
linuxlinux_kernel>= 6.7 < 6.11.86.11.8
msrcazl3_kernel_6.6.57.1-7_on_azure_linux_3.0
msrcazl3_kernel_6.6.64.2-1_on_azure_linux_3.0
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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