- 03 1月, 2019 8 次提交
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由 Daniel Borkmann 提交于
Jann reported that the original commit back in b2157399 ("bpf: prevent out-of-bounds speculation") was not sufficient to stop CPU from speculating out of bounds memory access: While b2157399 only focussed on masking array map access for unprivileged users for tail calls and data access such that the user provided index gets sanitized from BPF program and syscall side, there is still a more generic form affected from BPF programs that applies to most maps that hold user data in relation to dynamic map access when dealing with unknown scalars or "slow" known scalars as access offset, for example: - Load a map value pointer into R6 - Load an index into R7 - Do a slow computation (e.g. with a memory dependency) that loads a limit into R8 (e.g. load the limit from a map for high latency, then mask it to make the verifier happy) - Exit if R7 >= R8 (mispredicted branch) - Load R0 = R6[R7] - Load R0 = R6[R0] For unknown scalars there are two options in the BPF verifier where we could derive knowledge from in order to guarantee safe access to the memory: i) While </>/<=/>= variants won't allow to derive any lower or upper bounds from the unknown scalar where it would be safe to add it to the map value pointer, it is possible through ==/!= test however. ii) another option is to transform the unknown scalar into a known scalar, for example, through ALU ops combination such as R &= <imm> followed by R |= <imm> or any similar combination where the original information from the unknown scalar would be destroyed entirely leaving R with a constant. The initial slow load still precedes the latter ALU ops on that register, so the CPU executes speculatively from that point. Once we have the known scalar, any compare operation would work then. A third option only involving registers with known scalars could be crafted as described in [0] where a CPU port (e.g. Slow Int unit) would be filled with many dependent computations such that the subsequent condition depending on its outcome has to wait for evaluation on its execution port and thereby executing speculatively if the speculated code can be scheduled on a different execution port, or any other form of mistraining as described in [1], for example. Given this is not limited to only unknown scalars, not only map but also stack access is affected since both is accessible for unprivileged users and could potentially be used for out of bounds access under speculation. In order to prevent any of these cases, the verifier is now sanitizing pointer arithmetic on the offset such that any out of bounds speculation would be masked in a way where the pointer arithmetic result in the destination register will stay unchanged, meaning offset masked into zero similar as in array_index_nospec() case. With regards to implementation, there are three options that were considered: i) new insn for sanitation, ii) push/pop insn and sanitation as inlined BPF, iii) reuse of ax register and sanitation as inlined BPF. Option i) has the downside that we end up using from reserved bits in the opcode space, but also that we would require each JIT to emit masking as native arch opcodes meaning mitigation would have slow adoption till everyone implements it eventually which is counter-productive. Option ii) and iii) have both in common that a temporary register is needed in order to implement the sanitation as inlined BPF since we are not allowed to modify the source register. While a push / pop insn in ii) would be useful to have in any case, it requires once again that every JIT needs to implement it first. While possible, amount of changes needed would also be unsuitable for a -stable patch. Therefore, the path which has fewer changes, less BPF instructions for the mitigation and does not require anything to be changed in the JITs is option iii) which this work is pursuing. The ax register is already mapped to a register in all JITs (modulo arm32 where it's mapped to stack as various other BPF registers there) and used in constant blinding for JITs-only so far. It can be reused for verifier rewrites under certain constraints. The interpreter's tmp "register" has therefore been remapped into extending the register set with hidden ax register and reusing that for a number of instructions that needed the prior temporary variable internally (e.g. div, mod). This allows for zero increase in stack space usage in the interpreter, and enables (restricted) generic use in rewrites otherwise as long as such a patchlet does not make use of these instructions. The sanitation mask is dynamic and relative to the offset the map value or stack pointer currently holds. There are various cases that need to be taken under consideration for the masking, e.g. such operation could look as follows: ptr += val or val += ptr or ptr -= val. Thus, the value to be sanitized could reside either in source or in destination register, and the limit is different depending on whether the ALU op is addition or subtraction and depending on the current known and bounded offset. The limit is derived as follows: limit := max_value_size - (smin_value + off). For subtraction: limit := umax_value + off. This holds because we do not allow any pointer arithmetic that would temporarily go out of bounds or would have an unknown value with mixed signed bounds where it is unclear at verification time whether the actual runtime value would be either negative or positive. For example, we have a derived map pointer value with constant offset and bounded one, so limit based on smin_value works because the verifier requires that statically analyzed arithmetic on the pointer must be in bounds, and thus it checks if resulting smin_value + off and umax_value + off is still within map value bounds at time of arithmetic in addition to time of access. Similarly, for the case of stack access we derive the limit as follows: MAX_BPF_STACK + off for subtraction and -off for the case of addition where off := ptr_reg->off + ptr_reg->var_off.value. Subtraction is a special case for the masking which can be in form of ptr += -val, ptr -= -val, or ptr -= val. In the first two cases where we know that the value is negative, we need to temporarily negate the value in order to do the sanitation on a positive value where we later swap the ALU op, and restore original source register if the value was in source. The sanitation of pointer arithmetic alone is still not fully sufficient as is, since a scenario like the following could happen ... PTR += 0x1000 (e.g. K-based imm) PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON PTR += 0x1000 PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON [...] ... which under speculation could end up as ... PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] [...] ... and therefore still access out of bounds. To prevent such case, the verifier is also analyzing safety for potential out of bounds access under speculative execution. Meaning, it is also simulating pointer access under truncation. We therefore "branch off" and push the current verification state after the ALU operation with known 0 to the verification stack for later analysis. Given the current path analysis succeeded it is likely that the one under speculation can be pruned. In any case, it is also subject to existing complexity limits and therefore anything beyond this point will be rejected. In terms of pruning, it needs to be ensured that the verification state from speculative execution simulation must never prune a non-speculative execution path, therefore, we mark verifier state accordingly at the time of push_stack(). If verifier detects out of bounds access under speculative execution from one of the possible paths that includes a truncation, it will reject such program. Given we mask every reg-based pointer arithmetic for unprivileged programs, we've been looking into how it could affect real-world programs in terms of size increase. As the majority of programs are targeted for privileged-only use case, we've unconditionally enabled masking (with its alu restrictions on top of it) for privileged programs for the sake of testing in order to check i) whether they get rejected in its current form, and ii) by how much the number of instructions and size will increase. We've tested this by using Katran, Cilium and test_l4lb from the kernel selftests. For Katran we've evaluated balancer_kern.o, Cilium bpf_lxc.o and an older test object bpf_lxc_opt_-DUNKNOWN.o and l4lb we've used test_l4lb.o as well as test_l4lb_noinline.o. We found that none of the programs got rejected by the verifier with this change, and that impact is rather minimal to none. balancer_kern.o had 13,904 bytes (1,738 insns) xlated and 7,797 bytes JITed before and after the change. Most complex program in bpf_lxc.o had 30,544 bytes (3,817 insns) xlated and 18,538 bytes JITed before and after and none of the other tail call programs in bpf_lxc.o had any changes either. For the older bpf_lxc_opt_-DUNKNOWN.o object we found a small increase from 20,616 bytes (2,576 insns) and 12,536 bytes JITed before to 20,664 bytes (2,582 insns) and 12,558 bytes JITed after the change. Other programs from that object file had similar small increase. Both test_l4lb.o had no change and remained at 6,544 bytes (817 insns) xlated and 3,401 bytes JITed and for test_l4lb_noinline.o constant at 5,080 bytes (634 insns) xlated and 3,313 bytes JITed. This can be explained in that LLVM typically optimizes stack based pointer arithmetic by using K-based operations and that use of dynamic map access is not overly frequent. However, in future we may decide to optimize the algorithm further under known guarantees from branch and value speculation. Latter seems also unclear in terms of prediction heuristics that today's CPUs apply as well as whether there could be collisions in e.g. the predictor's Value History/Pattern Table for triggering out of bounds access, thus masking is performed unconditionally at this point but could be subject to relaxation later on. We were generally also brainstorming various other approaches for mitigation, but the blocker was always lack of available registers at runtime and/or overhead for runtime tracking of limits belonging to a specific pointer. Thus, we found this to be minimally intrusive under given constraints. With that in place, a simple example with sanitized access on unprivileged load at post-verification time looks as follows: # bpftool prog dump xlated id 282 [...] 28: (79) r1 = *(u64 *)(r7 +0) 29: (79) r2 = *(u64 *)(r7 +8) 30: (57) r1 &= 15 31: (79) r3 = *(u64 *)(r0 +4608) 32: (57) r3 &= 1 33: (47) r3 |= 1 34: (2d) if r2 > r3 goto pc+19 35: (b4) (u32) r11 = (u32) 20479 | 36: (1f) r11 -= r2 | Dynamic sanitation for pointer 37: (4f) r11 |= r2 | arithmetic with registers 38: (87) r11 = -r11 | containing bounded or known 39: (c7) r11 s>>= 63 | scalars in order to prevent 40: (5f) r11 &= r2 | out of bounds speculation. 41: (0f) r4 += r11 | 42: (71) r4 = *(u8 *)(r4 +0) 43: (6f) r4 <<= r1 [...] For the case where the scalar sits in the destination register as opposed to the source register, the following code is emitted for the above example: [...] 16: (b4) (u32) r11 = (u32) 20479 17: (1f) r11 -= r2 18: (4f) r11 |= r2 19: (87) r11 = -r11 20: (c7) r11 s>>= 63 21: (5f) r2 &= r11 22: (0f) r2 += r0 23: (61) r0 = *(u32 *)(r2 +0) [...] JIT blinding example with non-conflicting use of r10: [...] d5: je 0x0000000000000106 _ d7: mov 0x0(%rax),%edi | da: mov $0xf153246,%r10d | Index load from map value and e0: xor $0xf153259,%r10 | (const blinded) mask with 0x1f. e7: and %r10,%rdi |_ ea: mov $0x2f,%r10d | f0: sub %rdi,%r10 | Sanitized addition. Both use r10 f3: or %rdi,%r10 | but do not interfere with each f6: neg %r10 | other. (Neither do these instructions f9: sar $0x3f,%r10 | interfere with the use of ax as temp fd: and %r10,%rdi | in interpreter.) 100: add %rax,%rdi |_ 103: mov 0x0(%rdi),%eax [...] Tested that it fixes Jann's reproducer, and also checked that test_verifier and test_progs suite with interpreter, JIT and JIT with hardening enabled on x86-64 and arm64 runs successfully. [0] Speculose: Analyzing the Security Implications of Speculative Execution in CPUs, Giorgi Maisuradze and Christian Rossow, https://arxiv.org/pdf/1801.04084.pdf [1] A Systematic Evaluation of Transient Execution Attacks and Defenses, Claudio Canella, Jo Van Bulck, Michael Schwarz, Moritz Lipp, Benjamin von Berg, Philipp Ortner, Frank Piessens, Dmitry Evtyushkin, Daniel Gruss, https://arxiv.org/pdf/1811.05441.pdf Fixes: b2157399 ("bpf: prevent out-of-bounds speculation") Reported-by: NJann Horn <jannh@google.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
In check_map_access() we probe actual bounds through __check_map_access() with offset of reg->smin_value + off for lower bound and offset of reg->umax_value + off for the upper bound. However, even though the reg->smin_value could have a negative value, the final result of the sum with off could be positive when pointer arithmetic with known and unknown scalars is combined. In this case we reject the program with an error such as "R<x> min value is negative, either use unsigned index or do a if (index >=0) check." even though the access itself would be fine. Therefore extend the check to probe whether the actual resulting reg->smin_value + off is less than zero. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
For unknown scalars of mixed signed bounds, meaning their smin_value is negative and their smax_value is positive, we need to reject arithmetic with pointer to map value. For unprivileged the goal is to mask every map pointer arithmetic and this cannot reliably be done when it is unknown at verification time whether the scalar value is negative or positive. Given this is a corner case, the likelihood of breaking should be very small. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
Restrict stack pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a stack pointer as a destination we simulate a check_stack_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. This is analog to map value pointer arithmetic and needed for masking later on. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
Restrict map value pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a map value pointer as a destination it will simulate a check_map_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. We use this later on for masking any pointer arithmetic with the remainder of the map value space. The likelihood of breaking any existing real-world unprivileged eBPF program is very small for this corner case. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
Right now we are using BPF ax register in JIT for constant blinding as well as in interpreter as temporary variable. Verifier will not be able to use it simply because its use will get overridden from the former in bpf_jit_blind_insn(). However, it can be made to work in that blinding will be skipped if there is prior use in either source or destination register on the instruction. Taking constraints of ax into account, the verifier is then open to use it in rewrites under some constraints. Note, ax register already has mappings in every eBPF JIT. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
This change moves the on-stack 64 bit tmp variable in ___bpf_prog_run() into the hidden ax register. The latter is currently only used in JITs for constant blinding as a temporary scratch register, meaning the BPF interpreter will never see the use of ax. Therefore it is safe to use it for the cases where tmp has been used earlier. This is needed to later on allow restricted hidden use of ax in both interpreter and JITs. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
Move prev_insn_idx and insn_idx from the do_check() function into the verifier environment, so they can be read inside the various helper functions for handling the instructions. It's easier to put this into the environment rather than changing all call-sites only to pass it along. insn_idx is useful in particular since this later on allows to hold state in env->insn_aux_data[env->insn_idx]. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 01 1月, 2019 2 次提交
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由 Xiaozhou Liu 提交于
As a simple fix, just print the correct map type. Signed-off-by: NXiaozhou Liu <liuxiaozhou@bytedance.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Tyrel Datwyler 提交于
Commit 33a48ab1 ("ibmveth: Fix DMA unmap error") fixed an issue in the normal code path of ibmveth_xmit_start() that was originally introduced by Commit 6e8ab30e ("ibmveth: Add scatter-gather support"). This original fix missed the error path where dma_unmap_page is wrongly called on the header portion in descs[0] which was mapped with dma_map_single. As a result a failure to DMA map any of the frags results in a dmesg warning when CONFIG_DMA_API_DEBUG is enabled. ------------[ cut here ]------------ DMA-API: ibmveth 30000002: device driver frees DMA memory with wrong function [device address=0x000000000a430000] [size=172 bytes] [mapped as page] [unmapped as single] WARNING: CPU: 1 PID: 8426 at kernel/dma/debug.c:1085 check_unmap+0x4fc/0xe10 ... <snip> ... DMA-API: Mapped at: ibmveth_start_xmit+0x30c/0xb60 dev_hard_start_xmit+0x100/0x450 sch_direct_xmit+0x224/0x490 __qdisc_run+0x20c/0x980 __dev_queue_xmit+0x1bc/0xf20 This fixes the API misuse by unampping descs[0] with dma_unmap_single. Fixes: 6e8ab30e ("ibmveth: Add scatter-gather support") Signed-off-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 31 12月, 2018 8 次提交
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由 Heiner Kallweit 提交于
In rtl8169_runtime_resume() we configure WoL but don't set the device to wakeup-enabled. This prevents PME generation once the cable is re-plugged. Fix this by moving the call to device_set_wakeup_enable() to __rtl8169_set_wol(). Fixes: 433f9d0d ("r8169: improve saved_wolopts handling") Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Cong Wang 提交于
nr_find_socket(), nr_find_peer() and nr_find_listener() lock the sock after finding it in the global list. However, the call path requires BH disabled for the sock lock consistently. Actually the locking is unnecessary at this point, we can just hold the sock refcnt to make sure it is not gone after we unlock the global list, and lock it later only when needed. Reported-and-tested-by: syzbot+f621cda8b7e598908efa@syzkaller.appspotmail.com Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Cong Wang 提交于
When x25_asy_open() fails, it already cleans up by itself, so its caller doesn't need to free the memory again. It seems we still have to call x25_asy_free() to clear the SLF_INUSE bit, so just set these pointers to NULL after kfree(). Reported-and-tested-by: syzbot+5e5e969e525129229052@syzkaller.appspotmail.com Fixes: 3b780bed ("x25_asy: Free x25_asy on x25_asy_open() failure.") Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Cong Wang 提交于
There are multiple issues here: 1. After freeing dev->ax25_ptr, we need to set it to NULL otherwise we may use a dangling pointer. 2. There is a race between ax25_setsockopt() and device notifier as reported by syzbot. Close it by holding RTNL lock. 3. We need to test if dev->ax25_ptr is NULL before using it. Reported-and-tested-by: syzbot+ae6bb869cbed29b29040@syzkaller.appspotmail.com Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Su Yanjun 提交于
Signed-off-by: NSu Yanjun <suyj.fnst@cn.fujitsu.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 YueHaibing 提交于
gcc warn this: net/ipv4/fib_rules.c:203 fib_empty_table() warn: always true condition '(id <= 4294967295) => (0-u32max <= u32max)' 'id' is u32, which always not greater than RT_TABLE_MAX (0xFFFFFFFF), So add a check to break while wrap around. Signed-off-by: NYueHaibing <yuehaibing@huawei.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Christophe JAILLET 提交于
'ipv6_find_idev()' returns NULL on error, not an error pointer. Update the test accordingly and return -ENOBUFS, as already done in 'addrconf_add_dev()', if NULL is returned. Fixes: ("ipv6: allow userspace to add IFA_F_OPTIMISTIC addresses") Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Nikolay Aleksandrov 提交于
We must have an address to lookup otherwise we'll derefence a null pointer in the ndo_fdb_get callbacks. CC: Roopa Prabhu <roopa@cumulusnetworks.com> CC: David Ahern <dsa@cumulusnetworks.com> Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com Fixes: 5b2f94b2 ("net: rtnetlink: support for fdb get") Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: NRoopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 12月, 2018 1 次提交
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git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf由 David S. Miller 提交于
Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net, specifically fixes for the nf_conncount infrastructure which is causing troubles since 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search"). Patches aim to simplify this infrastructure while fixing up the problems: 1) Use fixed size CONNCOUNT_SLOTS in nf_conncount, from Shawn Bohrer. 2) Incorrect signedness in age calculation from find_or_evict(), from Florian Westphal. 3) Proper locking for the garbage collector workqueue callback, first make a patch to count how many nodes can be collected without holding locks, then grab lock and release them. Also from Florian. 4) Restart node lookup from the insertion path, after releasing nodes via packet path garbage collection. Shawn Bohrer described a scenario that may result in inserting a connection in an already dead list node. Patch from Florian. 5) Merge lookup and add function to avoid a hold release and re-grab. From Florian. 6) Be safe and iterate over the node lists under the spinlock. 7) Speculative list nodes removal via garbage collection, check if list node got a connection while it was scheduled for deletion via gc. 8) Accidental argument swap in find_next_bit() that leads to more frequent scheduling of the workqueue. From Florian Westphal. ==================== Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 29 12月, 2018 12 次提交
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由 Scott Wood 提交于
These functions are called from atomic context: [ 9.150239] BUG: sleeping function called from invalid context at /home/scott/git/linux/mm/slab.h:421 [ 9.158159] in_atomic(): 1, irqs_disabled(): 0, pid: 4432, name: ip [ 9.163128] CPU: 8 PID: 4432 Comm: ip Not tainted 4.20.0-rc2-00169-g63d86876 #29 [ 9.163130] Call Trace: [ 9.170701] [c0000002e899a980] [c0000000009c1068] .dump_stack+0xa8/0xec (unreliable) [ 9.177140] [c0000002e899aa10] [c00000000007a7b4] .___might_sleep+0x138/0x164 [ 9.184440] [c0000002e899aa80] [c0000000001d5bac] .kmem_cache_alloc_trace+0x238/0x30c [ 9.191216] [c0000002e899ab40] [c00000000065ea1c] .memac_add_hash_mac_address+0x104/0x198 [ 9.199464] [c0000002e899abd0] [c00000000065a788] .set_multi+0x1c8/0x218 [ 9.206242] [c0000002e899ac80] [c0000000006615ec] .dpaa_set_rx_mode+0xdc/0x17c [ 9.213544] [c0000002e899ad00] [c00000000083d2b0] .__dev_set_rx_mode+0x80/0xd4 [ 9.219535] [c0000002e899ad90] [c00000000083d334] .dev_set_rx_mode+0x30/0x54 [ 9.225271] [c0000002e899ae10] [c00000000083d4a0] .__dev_open+0x148/0x1c8 [ 9.230751] [c0000002e899aeb0] [c00000000083d934] .__dev_change_flags+0x19c/0x1e0 [ 9.230755] [c0000002e899af60] [c00000000083d9a4] .dev_change_flags+0x2c/0x80 [ 9.242752] [c0000002e899aff0] [c0000000008554ec] .do_setlink+0x350/0xf08 [ 9.248228] [c0000002e899b170] [c000000000857ad0] .rtnl_newlink+0x588/0x7e0 [ 9.253965] [c0000002e899b740] [c000000000852424] .rtnetlink_rcv_msg+0x3e0/0x498 [ 9.261440] [c0000002e899b820] [c000000000884790] .netlink_rcv_skb+0x134/0x14c [ 9.267607] [c0000002e899b8e0] [c000000000851840] .rtnetlink_rcv+0x18/0x2c [ 9.274558] [c0000002e899b950] [c000000000883c8c] .netlink_unicast+0x214/0x318 [ 9.281163] [c0000002e899ba00] [c000000000884220] .netlink_sendmsg+0x348/0x444 [ 9.287076] [c0000002e899bae0] [c00000000080d13c] .sock_sendmsg+0x2c/0x54 [ 9.287080] [c0000002e899bb50] [c0000000008106c0] .___sys_sendmsg+0x2d0/0x2d8 [ 9.298375] [c0000002e899bd30] [c000000000811a80] .__sys_sendmsg+0x5c/0xb0 [ 9.303939] [c0000002e899be20] [c0000000000006b0] system_call+0x60/0x6c Signed-off-by: NScott Wood <oss@buserror.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jia-Ju Bai 提交于
In drivers/isdn/hisax/hfc_pci.c, the functions hfcpci_interrupt() and HFCPCI_l1hw() may be concurrently executed. HFCPCI_l1hw() line 1173: if (!cs->tx_skb) hfcpci_interrupt() line 942: spin_lock_irqsave(); line 1066: dev_kfree_skb_irq(cs->tx_skb); Thus, a possible concurrency use-after-free bug may occur in HFCPCI_l1hw(). To fix these bugs, the calls to spin_lock_irqsave() and spin_unlock_irqrestore() are added in HFCPCI_l1hw(), to protect the access to cs->tx_skb. Signed-off-by: NJia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yunsheng Lin 提交于
The return type for get_regs_len in struct ethtool_ops is int, the hns3 driver may return error when failing to get the regs len by sending cmd to firmware. Signed-off-by: NYunsheng Lin <linyunsheng@huawei.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Florian Westphal 提交于
Size and 'next bit' were swapped, this bug could cause worker to reschedule itself even if system was idle. Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search") Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Pablo Neira Ayuso 提交于
Instead of removing a empty list node that might be reintroduced soon thereafter, tentatively place the empty list node on the list passed to tree_nodes_free(), then re-check if the list is empty again before erasing it from the tree. [ Florian: rebase on top of pending nf_conncount fixes ] Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search") Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Pablo Neira Ayuso 提交于
Two CPUs may race to remove a connection from the list, the existing conn->dead will result in a use-after-free. Use the per-list spinlock to protect list iterations. As all accesses to the list now happen while holding the per-list lock, we no longer need to delay free operations with rcu. Joint work with Florian. Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search") Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Florian Westphal 提交于
'lookup' is always followed by 'add'. Merge both and make the list-walk part of nf_conncount_add(). This also avoids one unneeded unlock/re-lock pair. Extra care needs to be taken in count_tree, as we only hold rcu read lock, i.e. we can only insert to an existing tree node after acquiring its lock and making sure it has a nonzero count. As a zero count should be rare, just fall back to insert_tree() (which acquires tree lock). This issue and its solution were pointed out by Shawn Bohrer during patch review. Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Florian Westphal 提交于
Shawn Bohrer reported a following crash: |RIP: 0010:rb_erase+0xae/0x360 [..] Call Trace: nf_conncount_destroy+0x59/0xc0 [nf_conncount] cleanup_match+0x45/0x70 [ip_tables] ... Shawn tracked this down to bogus 'parent' pointer: Problem is that when we insert a new node, then there is a chance that the 'parent' that we found was also passed to tree_nodes_free() (because that node was empty) for erase+free. Instead of trying to be clever and detect when this happens, restart the search if we have evicted one or more nodes. To prevent frequent restarts, do not perform gc on the second round. Also, unconditionally schedule the gc worker. The condition gc_count > ARRAY_SIZE(gc_nodes)) cannot be true unless tree grows very large, as the height of the tree will be low even with hundreds of nodes present. Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search") Reported-by: NShawn Bohrer <sbohrer@cloudflare.com> Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Florian Westphal 提交于
The lockless workqueue garbage collector can race with packet path garbage collector to delete list nodes, as it calls tree_nodes_free() with the addresses of nodes that might have been free'd already from another cpu. To fix this, split gc into two phases. One phase to perform gc on the connections: From a locking perspective, this is the same as count_tree(): we hold rcu lock, but we do not change the tree, we only change the nodes' contents. The second phase acquires the tree lock and reaps empty nodes. This avoids a race condition of the garbage collection vs. packet path: If a node has been free'd already, the second phase won't find it anymore. This second phase is, from locking perspective, same as insert_tree(). The former only modifies nodes (list content, count), latter modifies the tree itself (rb_erase or rb_insert). Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search") Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Florian Westphal 提交于
age is signed integer, so result can be negative when the timestamps have a large delta. In this case we want to discard the entry. Instead of using age >= 2 || age < 0, just make it unsigned. Fixes: b36e4523 ("netfilter: nf_conncount: fix garbage collection confirm race") Reviewed-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Shawn Bohrer 提交于
Most of the time these were the same value anyway, but when CONFIG_LOCKDEP was enabled we would use a smaller number of locks to reduce overhead. Unfortunately having two values is confusing and not worth the complexity. This fixes a bug where tree_gc_worker() would only GC up to CONNCOUNT_LOCK_SLOTS trees which meant when CONFIG_LOCKDEP was enabled not all trees would be GCed by tree_gc_worker(). Fixes: 5c789e13 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search") Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NShawn Bohrer <sbohrer@cloudflare.com> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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由 Kangjie Lu 提交于
If nla_nest_start() may fail. The fix checks its return value and goes to nla_put_failure if it fails. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
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- 28 12月, 2018 9 次提交
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由 Robert P. J. Day 提交于
Correct two minor kerneldoc errors: 1) missing reference to @mode in struct phy_ops 2) obsolete reference to @init_data in struct_phy_attrs, removed in dbc98635Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Robert P. J. Day 提交于
1) note that gianfar_phy.c was removed years ago 2) fix obvious copy and paste error in regular doc 3) change regular doc into kerneldoc for phy_modes() Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Wen Yang 提交于
This patch fixes potential double frees if register_hdlc_device() fails. Signed-off-by: NWen Yang <wen.yang99@zte.com.cn> Reviewed-by: NPeng Hao <peng.hao2@zte.com.cn> CC: Zhao Qiang <qiang.zhao@nxp.com> CC: "David S. Miller" <davem@davemloft.net> CC: netdev@vger.kernel.org CC: linuxppc-dev@lists.ozlabs.org CC: linux-kernel@vger.kernel.org Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Kangjie Lu 提交于
When acpi_match_device fails, its return value is NULL. Directly using the return value without a check may result in a NULL-pointer dereference. The fix checks if acpi_match_device fails, and if so, returns -EINVAL. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Kangjie Lu 提交于
genlmsg_put could fail. The fix inserts a check of its return value, and if it fails, returns -EMSGSIZE. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Kangjie Lu 提交于
atl1e_write_phy_reg() could fail. The fix issues an error message when it fails. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Kangjie Lu 提交于
Both bcm_sf2_sw_indir_rw and mdiobus_write_nested could fail, so let's return their error codes upstream. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Kangjie Lu 提交于
clk_prepare() could fail, so let's check its status, and if it fails, return its error code upstream. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Kangjie Lu 提交于
clk_prepare() could fail, so let's check its status, and if it fails, return its error code upstream. Signed-off-by: NKangjie Lu <kjlu@umn.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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