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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	John Fastabend <john.fastabend@gmail.com>,
	Alexei Starovoitov <ast@kernel.org>
Subject: [PATCH 4.14 30/47] bpf: Rework ptr_limit into alu_limit and add common error path
Date: Tue,  8 Jun 2021 20:27:13 +0200
Message-ID: <20210608175931.466685613@linuxfoundation.org> (raw)
In-Reply-To: <20210608175930.477274100@linuxfoundation.org>

From: Daniel Borkmann <daniel@iogearbox.net>

commit b658bbb844e28f1862867f37e8ca11a8e2aa94a3 upstream.

Small refactor with no semantic changes in order to consolidate the max
ptr_limit boundary check.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 kernel/bpf/verifier.c |   21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2026,12 +2026,12 @@ static struct bpf_insn_aux_data *cur_aux
 
 static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg,
 			      const struct bpf_reg_state *off_reg,
-			      u32 *ptr_limit, u8 opcode)
+			      u32 *alu_limit, u8 opcode)
 {
 	bool off_is_neg = off_reg->smin_value < 0;
 	bool mask_to_left = (opcode == BPF_ADD &&  off_is_neg) ||
 			    (opcode == BPF_SUB && !off_is_neg);
-	u32 off, max;
+	u32 off, max = 0, ptr_limit = 0;
 
 	if (!tnum_is_const(off_reg->var_off) &&
 	    (off_reg->smin_value < 0) != (off_reg->smax_value < 0))
@@ -2045,22 +2045,27 @@ static int retrieve_ptr_limit(const stru
 		max = MAX_BPF_STACK + mask_to_left;
 		off = ptr_reg->off + ptr_reg->var_off.value;
 		if (mask_to_left)
-			*ptr_limit = MAX_BPF_STACK + off;
+			ptr_limit = MAX_BPF_STACK + off;
 		else
-			*ptr_limit = -off - 1;
-		return *ptr_limit >= max ? -ERANGE : 0;
+			ptr_limit = -off - 1;
+		break;
 	case PTR_TO_MAP_VALUE:
 		max = ptr_reg->map_ptr->value_size;
 		if (mask_to_left) {
-			*ptr_limit = ptr_reg->umax_value + ptr_reg->off;
+			ptr_limit = ptr_reg->umax_value + ptr_reg->off;
 		} else {
 			off = ptr_reg->smin_value + ptr_reg->off;
-			*ptr_limit = ptr_reg->map_ptr->value_size - off - 1;
+			ptr_limit = ptr_reg->map_ptr->value_size - off - 1;
 		}
-		return *ptr_limit >= max ? -ERANGE : 0;
+		break;
 	default:
 		return -EINVAL;
 	}
+
+	if (ptr_limit >= max)
+		return -ERANGE;
+	*alu_limit = ptr_limit;
+	return 0;
 }
 
 static bool can_skip_alu_sanitation(const struct bpf_verifier_env *env,



  parent reply index

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-08 18:26 [PATCH 4.14 00/47] 4.14.236-rc1 review Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 01/47] net: usb: cdc_ncm: dont spew notifications Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 02/47] efi: Allow EFI_MEMORY_XP and EFI_MEMORY_RO both to be cleared Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 03/47] efi: cper: fix snprintf() use in cper_dimm_err_location() Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 04/47] vfio/pci: Fix error return code in vfio_ecap_init() Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 05/47] vfio/pci: zap_vma_ptes() needs MMU Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 06/47] vfio/platform: fix module_put call in error flow Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 07/47] ipvs: ignore IP_VS_SVC_F_HASHED flag when adding service Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 08/47] HID: pidff: fix error return code in hid_pidff_init() Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 09/47] HID: i2c-hid: fix format string mismatch Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 10/47] netfilter: nfnetlink_cthelper: hit EBUSY on updates if size mismatches Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 11/47] ieee802154: fix error return code in ieee802154_add_iface() Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 12/47] ieee802154: fix error return code in ieee802154_llsec_getparams() Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 13/47] Bluetooth: fix the erroneous flush_work() order Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 14/47] Bluetooth: use correct lock to prevent UAF of hdev object Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 15/47] net: caif: added cfserl_release function Greg Kroah-Hartman
2021-06-08 18:26 ` [PATCH 4.14 16/47] net: caif: add proper error handling Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 17/47] net: caif: fix memory leak in caif_device_notify Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 18/47] net: caif: fix memory leak in cfusbl_device_notify Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 19/47] ALSA: timer: Fix master timer notification Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 20/47] ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 21/47] pid: take a reference when initializing `cad_pid` Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 22/47] ocfs2: fix data corruption by fallocate Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 23/47] nfc: fix NULL ptr dereference in llcp_sock_getname() after failed connect Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 24/47] btrfs: fix error handling in btrfs_del_csums Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 25/47] btrfs: fixup error handling in fixup_inode_link_counts Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 26/47] mm, hugetlb: fix simple resv_huge_pages underflow on UFFDIO_COPY Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 27/47] bpf, selftests: Fix up some test_verifier cases for unprivileged Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 28/47] bpf: Move off_reg into sanitize_ptr_alu Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 29/47] bpf: Ensure off_reg has no mixed signed bounds for all types Greg Kroah-Hartman
2021-06-08 18:27 ` Greg Kroah-Hartman [this message]
2021-06-08 18:27 ` [PATCH 4.14 31/47] bpf: Improve verifier error messages for users Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 32/47] bpf: Refactor and streamline bounds check into helper Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 33/47] bpf: Move sanitize_val_alu out of op switch Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 34/47] bpf: Tighten speculative pointer arithmetic mask Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 35/47] bpf: Update selftests to reflect new error states Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 36/47] bpf: do not allow root to mangle valid pointers Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 37/47] bpf/verifier: disallow pointer subtraction Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 38/47] selftests/bpf: fix test_align Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 39/47] selftests/bpf: make dubious pointer arithmetic test useful Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 40/47] bpf: Fix leakage of uninitialized bpf stack under speculation Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 41/47] bpf: Wrap aux data inside bpf_sanitize_info container Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 42/47] bpf: Fix mask direction swap upon off reg sign change Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 43/47] bpf: No need to simulate speculative domain for immediates Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 44/47] bnxt_en: Remove the setting of dev_port Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 45/47] KVM: SVM: Truncate GPR value for DR and CR accesses in !64-bit mode Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 46/47] sched/fair: Optimize select_idle_cpu Greg Kroah-Hartman
2021-06-08 18:27 ` [PATCH 4.14 47/47] xen-pciback: redo VF placement in the virtual topology Greg Kroah-Hartman
2021-06-09  9:33 ` [PATCH 4.14 00/47] 4.14.236-rc1 review Jon Hunter
2021-06-09 11:25 ` Naresh Kamboju
2021-06-09 18:48 ` Guenter Roeck

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