Bug 2334807 (CVE-2024-56743)

Summary:	CVE-2024-56743 kernel: nfs_common: must not hold RCU while calling nfsd_file_put_local
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2024-12-29 12:01:17 UTC

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

nfs_common: must not hold RCU while calling nfsd_file_put_local

Move holding the RCU from nfs_to_nfsd_file_put_local to
nfs_to_nfsd_net_put.  It is the call to nfs_to->nfsd_serv_put that
requires the RCU anyway (the puts for nfsd_file and netns were
combined to avoid an extra indirect reference but that
micro-optimization isn't possible now).

This fixes xfstests generic/013 and it triggering:

"Voluntary context switch within RCU read-side critical section!"

[  143.545738] Call Trace:
[  143.546206]  <TASK>
[  143.546625]  ? show_regs+0x6d/0x80
[  143.547267]  ? __warn+0x91/0x140
[  143.547951]  ? rcu_note_context_switch+0x496/0x5d0
[  143.548856]  ? report_bug+0x193/0x1a0
[  143.549557]  ? handle_bug+0x63/0xa0
[  143.550214]  ? exc_invalid_op+0x1d/0x80
[  143.550938]  ? asm_exc_invalid_op+0x1f/0x30
[  143.551736]  ? rcu_note_context_switch+0x496/0x5d0
[  143.552634]  ? wakeup_preempt+0x62/0x70
[  143.553358]  __schedule+0xaa/0x1380
[  143.554025]  ? _raw_spin_unlock_irqrestore+0x12/0x40
[  143.554958]  ? try_to_wake_up+0x1fe/0x6b0
[  143.555715]  ? wake_up_process+0x19/0x20
[  143.556452]  schedule+0x2e/0x120
[  143.557066]  schedule_preempt_disabled+0x19/0x30
[  143.557933]  rwsem_down_read_slowpath+0x24d/0x4a0
[  143.558818]  ? xfs_efi_item_format+0x50/0xc0 [xfs]
[  143.559894]  down_read+0x4e/0xb0
[  143.560519]  xlog_cil_commit+0x1b2/0xbc0 [xfs]
[  143.561460]  ? _raw_spin_unlock+0x12/0x30
[  143.562212]  ? xfs_inode_item_precommit+0xc7/0x220 [xfs]
[  143.563309]  ? xfs_trans_run_precommits+0x69/0xd0 [xfs]
[  143.564394]  __xfs_trans_commit+0xb5/0x330 [xfs]
[  143.565367]  xfs_trans_roll+0x48/0xc0 [xfs]
[  143.566262]  xfs_defer_trans_roll+0x57/0x100 [xfs]
[  143.567278]  xfs_defer_finish_noroll+0x27a/0x490 [xfs]
[  143.568342]  xfs_defer_finish+0x1a/0x80 [xfs]
[  143.569267]  xfs_bunmapi_range+0x4d/0xb0 [xfs]
[  143.570208]  xfs_itruncate_extents_flags+0x13d/0x230 [xfs]
[  143.571353]  xfs_free_eofblocks+0x12e/0x190 [xfs]
[  143.572359]  xfs_file_release+0x12d/0x140 [xfs]
[  143.573324]  __fput+0xe8/0x2d0
[  143.573922]  __fput_sync+0x1d/0x30
[  143.574574]  nfsd_filp_close+0x33/0x60 [nfsd]
[  143.575430]  nfsd_file_free+0x96/0x150 [nfsd]
[  143.576274]  nfsd_file_put+0xf7/0x1a0 [nfsd]
[  143.577104]  nfsd_file_put_local+0x18/0x30 [nfsd]
[  143.578070]  nfs_close_local_fh+0x101/0x110 [nfs_localio]
[  143.579079]  __put_nfs_open_context+0xc9/0x180 [nfs]
[  143.580031]  nfs_file_clear_open_context+0x4a/0x60 [nfs]
[  143.581038]  nfs_file_release+0x3e/0x60 [nfs]
[  143.581879]  __fput+0xe8/0x2d0
[  143.582464]  __fput_sync+0x1d/0x30
[  143.583108]  __x64_sys_close+0x41/0x80
[  143.583823]  x64_sys_call+0x189a/0x20d0
[  143.584552]  do_syscall_64+0x64/0x170
[  143.585240]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  143.586185] RIP: 0033:0x7f3c5153efd7

Comment 1 Avinash Hanwate 2024-12-30 05:11:44 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024122925-CVE-2024-56743-39a5@gregkh/T