From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Alexei Starovoitov <ast@kernel.org>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 42/90] bpf: Remove recursion prevention from rcu free callback
Date: Thu, 17 Sep 2020 22:14:07 -0400 [thread overview]
Message-ID: <20200918021455.2067301-42-sashal@kernel.org> (raw)
In-Reply-To: <20200918021455.2067301-1-sashal@kernel.org>
From: Thomas Gleixner <tglx@linutronix.de>
[ Upstream commit 8a37963c7ac9ecb7f86f8ebda020e3f8d6d7b8a0 ]
If an element is freed via RCU then recursion into BPF instrumentation
functions is not a concern. The element is already detached from the map
and the RCU callback does not hold any locks on which a kprobe, perf event
or tracepoint attached BPF program could deadlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145643.259118710@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/bpf/hashtab.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 8648d7d297081..1253261fdb3ba 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -427,15 +427,7 @@ static void htab_elem_free_rcu(struct rcu_head *head)
struct htab_elem *l = container_of(head, struct htab_elem, rcu);
struct bpf_htab *htab = l->htab;
- /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
- * we're calling kfree, otherwise deadlock is possible if kprobes
- * are placed somewhere inside of slub
- */
- preempt_disable();
- __this_cpu_inc(bpf_prog_active);
htab_elem_free(htab, l);
- __this_cpu_dec(bpf_prog_active);
- preempt_enable();
}
static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
--
2.25.1
next prev parent reply other threads:[~2020-09-18 2:27 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-18 2:13 [PATCH AUTOSEL 4.9 01/90] scsi: aacraid: fix illegal IO beyond last LBA Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 02/90] m68k: q40: Fix info-leak in rtc_ioctl Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 03/90] gma/gma500: fix a memory disclosure bug due to uninitialized bytes Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 04/90] ASoC: kirkwood: fix IRQ error handling Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 05/90] ata: sata_mv, avoid trigerrable BUG_ON Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 06/90] PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 07/90] clk/ti/adpll: allocate room for terminating null Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 08/90] mtd: cfi_cmdset_0002: don't free cfi->cfiq in error path of cfi_amdstd_setup() Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 09/90] mfd: mfd-core: Protect against NULL call-back function pointer Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 10/90] tracing: Adding NULL checks for trace_array descriptor pointer Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 11/90] bcache: fix a lost wake-up problem caused by mca_cannibalize_lock Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 12/90] RDMA/i40iw: Fix potential use after free Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 13/90] xfs: fix attr leaf header freemap.size underflow Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 14/90] RDMA/iw_cgxb4: Fix an error handling path in 'c4iw_connect()' Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 15/90] debugfs: Fix !DEBUG_FS debugfs_create_automount Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 16/90] CIFS: Properly process SMB3 lease breaks Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 17/90] kernel/sys.c: avoid copying possible padding bytes in copy_to_user Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 18/90] neigh_stat_seq_next() should increase position index Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 19/90] rt_cpu_seq_next " Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 20/90] seqlock: Require WRITE_ONCE surrounding raw_seqcount_barrier Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 21/90] media: ti-vpe: cal: Restrict DMA to avoid memory corruption Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 22/90] ACPI: EC: Reference count query handlers under lock Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 23/90] efi/arm: Defer probe of PCIe backed efifb on DT systems Sasha Levin
2020-09-18 6:25 ` Ard Biesheuvel
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 24/90] dmaengine: zynqmp_dma: fix burst length configuration Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 25/90] tracing: Set kernel_stack's caller size properly Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 26/90] ext4: make dioread_nolock the default Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 27/90] ar5523: Add USB ID of SMCWUSBT-G2 wireless adapter Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 28/90] Bluetooth: Fix refcount use-after-free issue Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 29/90] mm: pagewalk: fix termination condition in walk_pte_range() Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 30/90] Bluetooth: prefetch channel before killing sock Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 31/90] KVM: fix overflow of zero page refcount with ksm running Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 32/90] ALSA: hda: Clear RIRB status before reading WP Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 33/90] skbuff: fix a data race in skb_queue_len() Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 34/90] audit: CONFIG_CHANGE don't log internal bookkeeping as an event Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 35/90] selinux: sel_avc_get_stat_idx should increase position index Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 36/90] scsi: lpfc: Fix RQ buffer leakage when no IOCBs available Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 37/90] scsi: lpfc: Fix coverity errors in fmdi attribute handling Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 38/90] drm/omap: fix possible object reference leak Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 39/90] RDMA/rxe: Fix configuration of atomic queue pair attributes Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 40/90] KVM: x86: fix incorrect comparison in trace event Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 41/90] x86/pkeys: Add check for pkey "overflow" Sasha Levin
2020-09-18 2:14 ` Sasha Levin [this message]
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 43/90] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 44/90] media: go7007: Fix URB type for interrupt handling Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 45/90] Bluetooth: guard against controllers sending zero'd events Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 46/90] timekeeping: Prevent 32bit truncation in scale64_check_overflow() Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 47/90] drm/amdgpu: increase atombios cmd timeout Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 48/90] Bluetooth: L2CAP: handle l2cap config request during open state Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 49/90] media: tda10071: fix unsigned sign extension overflow Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 50/90] xfs: don't ever return a stale pointer from __xfs_dir3_free_read Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 51/90] tpm: ibmvtpm: Wait for buffer to be set before proceeding Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 52/90] tracing: Use address-of operator on section symbols Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 53/90] serial: 8250_port: Don't service RX FIFO if throttled Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 54/90] serial: 8250_omap: Fix sleeping function called from invalid context during probe Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 55/90] serial: 8250: 8250_omap: Terminate DMA before pushing data on RX timeout Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 56/90] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 57/90] tools: gpio-hammer: Avoid potential overflow in main Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 58/90] SUNRPC: Fix a potential buffer overflow in 'svc_print_xprts()' Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 59/90] svcrdma: Fix leak of transport addresses Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 60/90] ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 61/90] ALSA: usb-audio: Fix case when USB MIDI interface has more than one extra endpoint descriptor Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 62/90] mm/filemap.c: clear page error before actual read Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 63/90] mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 64/90] serial: uartps: Wait for tx_empty in console setup Sasha Levin
2020-09-28 20:11 ` Naresh Kamboju
2020-09-28 20:13 ` Naresh Kamboju
2020-09-29 6:59 ` Greg Kroah-Hartman
2020-09-29 17:39 ` Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 65/90] KVM: Remove CREATE_IRQCHIP/SET_PIT2 race Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 66/90] bdev: Reduce time holding bd_mutex in sync in blkdev_close() Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 67/90] drivers: char: tlclk.c: Avoid data race between init and interrupt handler Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 68/90] dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 69/90] atm: fix a memory leak of vcc->user_back Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 70/90] phy: samsung: s5pv210-usb2: Add delay after reset Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 71/90] Bluetooth: Handle Inquiry Cancel error after Inquiry Complete Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 72/90] USB: EHCI: ehci-mv: fix error handling in mv_ehci_probe() Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 73/90] tty: serial: samsung: Correct clock selection logic Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 74/90] ALSA: hda: Fix potential race in unsol event handler Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 75/90] fuse: don't check refcount after stealing page Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 76/90] USB: EHCI: ehci-mv: fix less than zero comparison of an unsigned int Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 77/90] e1000: Do not perform reset in reset_task if we are already down Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 78/90] printk: handle blank console arguments passed in Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 79/90] btrfs: don't force read-only after error in drop snapshot Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 80/90] vfio/pci: fix memory leaks of eventfd ctx Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 81/90] perf util: Fix memory leak of prefix_if_not_in Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 82/90] perf kcore_copy: Fix module map when there are no modules loaded Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 83/90] mtd: rawnand: omap_elm: Fix runtime PM imbalance on error Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 84/90] ceph: fix potential race in ceph_check_caps Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 85/90] mtd: parser: cmdline: Support MTD names containing one or more colons Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 86/90] x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 87/90] vfio/pci: Clear error and request eventfd ctx after releasing Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 88/90] cifs: Fix double add page to memcg when cifs_readpages Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 89/90] selftests/x86/syscall_nt: Clear weird flags after each test Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 90/90] vfio/pci: fix racy on error and request eventfd ctx Sasha Levin
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