- 20 Sep, 2017 40 commits
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Brian Foster authored
commit cfaf2d03 upstream. If a dquot has an id of U32_MAX, the next lookup index increment overflows the uint32_t back to 0. This starts the lookup sequence over from the beginning, repeats indefinitely and results in a livelock. Update xfs_qm_dquot_walk() to explicitly check for the lookup overflow and exit the loop. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Darrick J. Wong authored
commit 10479e2d upstream. In some circumstances, _alloc_read_agf can return an error code of zero but also a null AGF buffer pointer. Check for this and jump out. Fixes-coverity-id: 1415250 Fixes-coverity-id: 1415320 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Darrick J. Wong authored
commit 4c1a67bd upstream. We must initialize the firstfsb parameter to _bmapi_write so that it doesn't incorrectly treat stack garbage as a restriction on which AGs it can search for free space. Fixes-coverity-id: 1402025 Fixes-coverity-id: 1415167 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Darrick J. Wong authored
commit 1e86eabe upstream. Check the _btree_check_block return value for the firstrec and lastrec functions, since we have the ability to signal that the repositioning did not succeed. Fixes-coverity-id: 114067 Fixes-coverity-id: 114068 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Darrick J. Wong authored
commit cd87d867 upstream. In quite a few places we call xfs_da_read_buf with a mappedbno that we don't control, then assume that the function passes back either an error code or a buffer pointer. Unfortunately, if mappedbno == -2 and bno maps to a hole, we get a return code of zero and a NULL buffer, which means that we crash if we actually try to use that buffer pointer. This happens immediately when we set the buffer type for transaction context. Therefore, check that we have no error code and a non-NULL bp before trying to use bp. This patch is a follow-up to an incomplete fix in 96a3aefb ("xfs: don't crash if reading a directory results in an unexpected hole"). Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Brian Foster authored
commit cf2cb784 upstream. XFS runs an eofblocks reclaim scan before returning an ENOSPC error to userspace for buffered writes. This facilitates aggressive speculative preallocation without causing user visible side effects such as premature ENOSPC. Run a cowblocks scan in the same situation to reclaim lingering COW fork preallocation throughout the filesystem. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Brian Foster authored
commit 39775431 upstream. Log recovery allocates in-core transaction and member item data structures on-demand as it processes the on-disk log. Transactions are allocated on first encounter on-disk and stored in a hash table structure where they are easily accessible for subsequent lookups. Transaction items are also allocated on demand and are attached to the associated transactions. When a commit record is encountered in the log, the transaction is committed to the fs and the in-core structures are freed. If a filesystem crashes or shuts down before all in-core log buffers are flushed to the log, however, not all transactions may have commit records in the log. As expected, the modifications in such an incomplete transaction are not replayed to the fs. The in-core data structures for the partial transaction are never freed, however, resulting in a memory leak. Update xlog_do_recovery_pass() to first correctly initialize the hash table array so empty lists can be distinguished from populated lists on function exit. Update xlog_recover_free_trans() to always remove the transaction from the list prior to freeing the associated memory. Finally, walk the hash table of transaction lists as the last step before it goes out of scope and free any transactions that may remain on the lists. This prevents a memory leak of partial transactions in the log. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Darrick J. Wong authored
commit 61d819e7 upstream. bmap returns a dumb LBA address but not the block device that goes with that LBA. Swapfiles don't care about this and will blindly assume that the data volume is the correct blockdev, which is totally bogus for files on the rt subvolume. This results in the swap code doing IOs to arbitrary locations on the data device(!) if the passed in mapping is a realtime file, so just turn off bmap for rt files. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Brian Foster authored
commit 3d4b4a3e upstream. When a buffer is modified, logged and committed, it ultimately ends up sitting on the AIL with a dirty bli waiting for metadata writeback. If another transaction locks and invalidates the buffer (freeing an inode chunk, for example) in the meantime, the bli is flagged as stale, the dirty state is cleared and the bli remains in the AIL. If a shutdown occurs before the transaction that has invalidated the buffer is committed, the transaction is ultimately aborted. The log items are flagged as such and ->iop_unlock() handles the aborted items. Because the bli is clean (due to the invalidation), ->iop_unlock() unconditionally releases it. The log item may still reside in the AIL, however, which means the I/O completion handler may still run and attempt to access it. This results in assert failure due to the release of the bli while still present in the AIL and a subsequent NULL dereference and panic in the buffer I/O completion handling. This can be reproduced by running generic/388 in repetition. To avoid this problem, update xfs_buf_item_unlock() to first check whether the bli is aborted and if so, remove it from the AIL before it is released. This ensures that the bli is no longer accessed during the shutdown sequence after it has been freed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Brian Foster authored
commit 79e641ce upstream. If a filesystem shutdown occurs with a buffer log item in the CIL and a log force occurs, the ->iop_unpin() handler is generally expected to tear down the bli properly. This entails freeing the bli memory and releasing the associated hold on the buffer so it can be released and the filesystem unmounted. If this sequence occurs while ->bli_refcount is elevated (i.e., another transaction is open and attempting to modify the buffer), however, ->iop_unpin() may not be responsible for releasing the bli. Instead, the transaction may release the final ->bli_refcount reference and thus xfs_trans_brelse() is responsible for tearing down the bli. While xfs_trans_brelse() does drop the reference count, it only attempts to release the bli if it is clean (i.e., not in the CIL/AIL). If the filesystem is shutdown and the bli is sitting dirty in the CIL as noted above, this ends up skipping the last opportunity to release the bli. In turn, this leaves the hold on the buffer and causes an unmount hang. This can be reproduced by running generic/388 in repetition. Update xfs_trans_brelse() to handle this shutdown corner case correctly. If the final bli reference is dropped and the filesystem is shutdown, remove the bli from the AIL (if necessary) and release the bli to drop the buffer hold and ensure an unmount does not hang. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Darrick J. Wong authored
commit e1a4e37c upstream. In a pathological scenario where we are trying to bunmapi a single extent in which every other block is shared, it's possible that trying to unmap the entire large extent in a single transaction can generate so many EFIs that we overflow the transaction reservation. Therefore, use a heuristic to guess at the number of blocks we can safely unmap from a reflink file's data fork in an single transaction. This should prevent problems such as the log head slamming into the tail and ASSERTs that trigger because we've exceeded the transaction reservation. Note that since bunmapi can fail to unmap the entire range, we must also teach the deferred unmap code to roll into a new transaction whenever we get low on reservation. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: random edits, all bugs are my fault] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Brian Foster authored
commit 7912e7fe upstream. Reclaim during quotacheck can lead to deadlocks on the dquot flush lock: - Quotacheck populates a local delwri queue with the physical dquot buffers. - Quotacheck performs the xfs_qm_dqusage_adjust() bulkstat and dirties all of the dquots. - Reclaim kicks in and attempts to flush a dquot whose buffer is already queud on the quotacheck queue. The flush succeeds but queueing to the reclaim delwri queue fails as the backing buffer is already queued. The flush unlock is now deferred to I/O completion of the buffer from the quotacheck queue. - The dqadjust bulkstat continues and dirties the recently flushed dquot once again. - Quotacheck proceeds to the xfs_qm_flush_one() walk which requires the flush lock to update the backing buffers with the in-core recalculated values. It deadlocks on the redirtied dquot as the flush lock was already acquired by reclaim, but the buffer resides on the local delwri queue which isn't submitted until the end of quotacheck. This is reproduced by running quotacheck on a filesystem with a couple million inodes in low memory (512MB-1GB) situations. This is a regression as of commit 43ff2122 ("xfs: on-stack delayed write buffer lists"), which removed a trylock and buffer I/O submission from the quotacheck dquot flush sequence. Quotacheck first resets and collects the physical dquot buffers in a delwri queue. Then, it traverses the filesystem inodes via bulkstat, updates the in-core dquots, flushes the corrected dquots to the backing buffers and finally submits the delwri queue for I/O. Since the backing buffers are queued across the entire quotacheck operation, dquot reclaim cannot possibly complete a dquot flush before quotacheck completes. Therefore, quotacheck must submit the buffer for I/O in order to cycle the flush lock and flush the dirty in-core dquot to the buffer. Add a delwri queue buffer push mechanism to submit an individual buffer for I/O without losing the delwri queue status and use it from quotacheck to avoid the deadlock. This restores quotacheck behavior to as before the regression was introduced. Reported-by: Martin Svec <martin.svec@zoner.cz> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Brian Foster authored
commit 95989c46 upstream. The 0-day kernel test robot reports assertion failures on !CONFIG_SMP kernels due to failed spin_is_locked() checks. As it turns out, spin_is_locked() is hardcoded to return zero on !CONFIG_SMP kernels and so this function cannot be relied on to verify spinlock state in this configuration. To avoid this problem, replace the associated asserts with lockdep variants that do the right thing regardless of kernel configuration. Drop the one assert that checks for an unlocked lock as there is no suitable lockdep variant for that case. This moves the spinlock checks from XFS debug code to lockdep, but generally provides the same level of protection. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jan Kara authored
commit a54fba8f upstream. Currently several places in xfs_find_get_desired_pgoff() handle the case of a missing page. Make them all handled in one place after the loop has terminated. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andy Lutomirski authored
commit e137a4d8 upstream. Switching FS and GS is a mess, and the current code is still subtly wrong: it assumes that "Loading a nonzero value into FS sets the index and base", which is false on AMD CPUs if the value being loaded is 1, 2, or 3. (The current code came from commit 3e2b68d7 ("x86/asm, sched/x86: Rewrite the FS and GS context switch code"), which made it better but didn't fully fix it.) Rewrite it to be much simpler and more obviously correct. This should fix it fully on AMD CPUs and shouldn't adversely affect performance. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang Seok <chang.seok.bae@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andy Lutomirski authored
commit 9584d98b upstream. In ELF_COPY_CORE_REGS, we're copying from the current task, so accessing thread.fsbase and thread.gsbase makes no sense. Just read the values from the CPU registers. In practice, the old code would have been correct most of the time simply because thread.fsbase and thread.gsbase usually matched the CPU registers. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang Seok <chang.seok.bae@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andy Lutomirski authored
commit 767d035d upstream. execve used to leak FSBASE and GSBASE on AMD CPUs. Fix it. The security impact of this bug is small but not quite zero -- it could weaken ASLR when a privileged task execs a less privileged program, but only if program changed bitness across the exec, or the child binary was highly unusual or actively malicious. A child program that was compromised after the exec would not have access to the leaked base. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang Seok <chang.seok.bae@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jaegeuk Kim authored
commit 125c9fb1 upstream. We need to check HOT_DATA to truncate any previous data block when doing roll-forward recovery. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jaegeuk Kim authored
commit afd2b4da upstream. If we set CP_ERROR_FLAG in roll-forward error, f2fs is no longer to proceed any IOs due to f2fs_cp_error(). But, for example, if some stale data is involved on roll-forward process, we're able to get -ENOENT, getting fs stuck. If we get any error, let fill_super set SBI_NEED_FSCK and try to recover back to stable point. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Haishuang Yan authored
[ Upstream commit 0f693f19 ] ttl and tos variables are declared and assigned, but are not used in iptunnel_xmit() function. Fixes: cfc7381b ("ip_tunnel: add collect_md mode to IPIP tunnel") Cc: Alexei Starovoitov <ast@fb.com> Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Marcelo Ricardo Leitner authored
[ Upstream commit 7906b00f ] Commit fb586f25 ("sctp: delay calls to sk_data_ready() as much as possible") minimized the number of wake ups that are triggered in case the association receives a packet with multiple data chunks on it and/or when io_events are enabled and then commit 0970f5b3 ("sctp: signal sk_data_ready earlier on data chunks reception") moved the wake up to as soon as possible. It thus relies on the state machine running later to clean the flag that the event was already generated. The issue is that there are 2 call paths that calls sctp_ulpq_tail_event() outside of the state machine, causing the flag to linger and possibly omitting a needed wake up in the sequence. One of the call paths is when enabling SCTP_SENDER_DRY_EVENTS via setsockopt(SCTP_EVENTS), as noticed by Harald Welte. The other is when partial reliability triggers removal of chunks from the send queue when the application calls sendmsg(). This commit fixes it by not setting the flag in case the socket is not owned by the user, as it won't be cleaned later. This works for user-initiated calls and also for rx path processing. Fixes: fb586f25 ("sctp: delay calls to sk_data_ready() as much as possible") Reported-by: Harald Welte <laforge@gnumonks.org> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Eric Dumazet authored
[ Upstream commit 32a805ba ] IPv6 FIB should use FIB6_TABLE_HASHSZ, not FIB_TABLE_HASHSZ. Fixes: ba1cc08d ("ipv6: fix memory leak with multiple tables during netns destruction") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Sabrina Dubroca authored
[ Upstream commit ba1cc08d ] fib6_net_exit only frees the main and local tables. If another table was created with fib6_alloc_table, we leak it when the netns is destroyed. Fix this in the same way ip_fib_net_exit cleans up tables, by walking through the whole hashtable of fib6_table's. We can get rid of the special cases for local and main, since they're also part of the hashtable. Reproducer: ip netns add x ip -net x -6 rule add from 6003:1::/64 table 100 ip netns del x Reported-by: Jianlin Shi <jishi@redhat.com> Fixes: 58f09b78 ("[NETNS][IPV6] ip6_fib - make it per network namespace") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Xin Long authored
[ Upstream commit 5c25f30c ] Now when probessing ICMPV6_PKT_TOOBIG, ip6gre_err only subtracts the offset of gre header from mtu info. The expected mtu of gre device should also subtract gre header. Otherwise, the next packets still can't be sent out. Jianlin found this issue when using the topo: client(ip6gre)<---->(nic1)route(nic2)<----->(ip6gre)server and reducing nic2's mtu, then both tcp and sctp's performance with big size data became 0. This patch is to fix it by also subtracting grehdr (tun->tun_hlen) from mtu info when updating gre device's mtu in ip6gre_err(). It also needs to subtract ETH_HLEN if gre dev'type is ARPHRD_ETHER. Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jason Wang authored
[ Upstream commit 8b949bef ] We check tx avail through vhost_enable_notify() in the past which is wrong since it only checks whether or not guest has filled more available buffer since last avail idx synchronization which was just done by vhost_vq_avail_empty() before. What we really want is checking pending buffers in the avail ring. Fix this by calling vhost_vq_avail_empty() instead. This issue could be noticed by doing netperf TCP_RR benchmark as client from guest (but not host). With this fix, TCP_RR from guest to localhost restores from 1375.91 trans per sec to 55235.28 trans per sec on my laptop (Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz). Fixes: 03088137 ("vhost_net: basic polling support") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Claudiu Manoil authored
[ Upstream commit 5d621672 ] The wrong register is checked for the Tx flow control bit, it should have been maccfg1 not maccfg2. This went unnoticed for so long probably because the impact is hardly visible, not to mention the tangled code from adjust_link(). First, link flow control (i.e. handling of Rx/Tx link level pause frames) is disabled by default (needs to be enabled via 'ethtool -A'). Secondly, maccfg2 always returns 0 for tx_flow_oldval (except for a few old boards), which results in Tx flow control remaining always on once activated. Fixes: 45b679c9 ("gianfar: Implement PAUSE frame generation support") Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jesper Dangaard Brouer authored
[ Upstream commit 5a63643e ] This reverts commit 1d6119ba. After reverting commit 6d7b857d ("net: use lib/percpu_counter API for fragmentation mem accounting") then here is no need for this fix-up patch. As percpu_counter is no longer used, it cannot memory leak it any-longer. Fixes: 6d7b857d ("net: use lib/percpu_counter API for fragmentation mem accounting") Fixes: 1d6119ba ("net: fix percpu memory leaks") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jesper Dangaard Brouer authored
[ Upstream commit fb452a1a ] This reverts commit 6d7b857d. There is a bug in fragmentation codes use of the percpu_counter API, that can cause issues on systems with many CPUs. The frag_mem_limit() just reads the global counter (fbc->count), without considering other CPUs can have upto batch size (130K) that haven't been subtracted yet. Due to the 3MBytes lower thresh limit, this become dangerous at >=24 CPUs (3*1024*1024/130000=24). The correct API usage would be to use __percpu_counter_compare() which does the right thing, and takes into account the number of (online) CPUs and batch size, to account for this and call __percpu_counter_sum() when needed. We choose to revert the use of the lib/percpu_counter API for frag memory accounting for several reasons: 1) On systems with CPUs > 24, the heavier fully locked __percpu_counter_sum() is always invoked, which will be more expensive than the atomic_t that is reverted to. Given systems with more than 24 CPUs are becoming common this doesn't seem like a good option. To mitigate this, the batch size could be decreased and thresh be increased. 2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX CPU, before SKBs are pushed into sockets on remote CPUs. Given NICs can only hash on L2 part of the IP-header, the NIC-RXq's will likely be limited. Thus, a fair chance that atomic add+dec happen on the same CPU. Revert note that commit 1d6119ba ("net: fix percpu memory leaks") removed init_frag_mem_limit() and instead use inet_frags_init_net(). After this revert, inet_frags_uninit_net() becomes empty. Fixes: 6d7b857d ("net: use lib/percpu_counter API for fragmentation mem accounting") Fixes: 1d6119ba ("net: fix percpu memory leaks") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ido Schimmel authored
[ Upstream commit 79e99bdd ] Commit 6bc506b4 ("bridge: switchdev: Add forward mark support for stacked devices") added the 'offload_fwd_mark' bit to the skb in order to allow drivers to indicate to the bridge driver that they already forwarded the packet in L2. In case the bit is set, before transmitting the packet from each port, the port's mark is compared with the mark stored in the skb's control block. If both marks are equal, we know the packet arrived from a switch device that already forwarded the packet and it's not re-transmitted. However, if the packet is transmitted from the bridge device itself (e.g., br0), we should clear the 'offload_fwd_mark' bit as the mark stored in the skb's control block isn't valid. This scenario can happen in rare cases where a packet was trapped during L3 forwarding and forwarded by the kernel to a bridge device. Fixes: 6bc506b4 ("bridge: switchdev: Add forward mark support for stacked devices") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Yotam Gigi <yotamg@mellanox.com> Tested-by: Yotam Gigi <yotamg@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ido Schimmel authored
[ Upstream commit 25cc72a3 ] The mlxsw driver relies on NETDEV_CHANGEUPPER events to configure the device in case a port is enslaved to a master netdev such as bridge or bond. Since the driver ignores events unrelated to its ports and their uppers, it's possible to engineer situations in which the device's data path differs from the kernel's. One example to such a situation is when a port is enslaved to a bond that is already enslaved to a bridge. When the bond was enslaved the driver ignored the event - as the bond wasn't one of its uppers - and therefore a bridge port instance isn't created in the device. Until such configurations are supported forbid them by checking that the upper device doesn't have uppers of its own. Fixes: 0d65fc13 ("mlxsw: spectrum: Implement LAG port join/leave") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Nogah Frankel <nogahf@mellanox.com> Tested-by: Nogah Frankel <nogahf@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Wei Wang authored
[ Upstream commit 499350a5 ] When tcp_disconnect() is called, inet_csk_delack_init() sets icsk->icsk_ack.rcv_mss to 0. This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() => __tcp_select_window() call path to have division by 0 issue. So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0. Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Florian Fainelli authored
[ Upstream commit ebc8254a ] This reverts commit 7ad813f2 ("net: phy: Correctly process PHY_HALTED in phy_stop_machine()") because it is creating the possibility for a NULL pointer dereference. David Daney provide the following call trace and diagram of events: When ndo_stop() is called we call: phy_disconnect() +---> phy_stop_interrupts() implies: phydev->irq = PHY_POLL; +---> phy_stop_machine() | +---> phy_state_machine() | +----> queue_delayed_work(): Work queued. +--->phy_detach() implies: phydev->attached_dev = NULL; Now at a later time the queued work does: phy_state_machine() +---->netif_carrier_off(phydev->attached_dev): Oh no! It is NULL: CPU 12 Unable to handle kernel paging request at virtual address 0000000000000048, epc == ffffffff80de37ec, ra == ffffffff80c7c Oops[#1]: CPU: 12 PID: 1502 Comm: kworker/12:1 Not tainted 4.9.43-Cavium-Octeon+ #1 Workqueue: events_power_efficient phy_state_machine task: 80000004021ed100 task.stack: 8000000409d70000 $ 0 : 0000000000000000 ffffffff84720060 0000000000000048 0000000000000004 $ 4 : 0000000000000000 0000000000000001 0000000000000004 0000000000000000 $ 8 : 0000000000000000 0000000000000000 00000000ffff98f3 0000000000000000 $12 : 8000000409d73fe0 0000000000009c00 ffffffff846547c8 000000000000af3b $16 : 80000004096bab68 80000004096babd0 0000000000000000 80000004096ba800 $20 : 0000000000000000 0000000000000000 ffffffff81090000 0000000000000008 $24 : 0000000000000061 ffffffff808637b0 $28 : 8000000409d70000 8000000409d73cf0 80000000271bd300 ffffffff80c7804c Hi : 000000000000002a Lo : 000000000000003f epc : ffffffff80de37ec netif_carrier_off+0xc/0x58 ra : ffffffff80c7804c phy_state_machine+0x48c/0x4f8 Status: 14009ce3 KX SX UX KERNEL EXL IE Cause : 00800008 (ExcCode 02) BadVA : 0000000000000048 PrId : 000d9501 (Cavium Octeon III) Modules linked in: Process kworker/12:1 (pid: 1502, threadinfo=8000000409d70000, task=80000004021ed100, tls=0000000000000000) Stack : 8000000409a54000 80000004096bab68 80000000271bd300 80000000271c1e00 0000000000000000 ffffffff808a1708 8000000409a54000 80000000271bd300 80000000271bd320 8000000409a54030 ffffffff80ff0f00 0000000000000001 ffffffff81090000 ffffffff808a1ac0 8000000402182080 ffffffff84650000 8000000402182080 ffffffff84650000 ffffffff80ff0000 8000000409a54000 ffffffff808a1970 0000000000000000 80000004099e8000 8000000402099240 0000000000000000 ffffffff808a8598 0000000000000000 8000000408eeeb00 8000000409a54000 00000000810a1d00 0000000000000000 8000000409d73de8 8000000409d73de8 0000000000000088 000000000c009c00 8000000409d73e08 8000000409d73e08 8000000402182080 ffffffff808a84d0 8000000402182080 ... Call Trace: [<ffffffff80de37ec>] netif_carrier_off+0xc/0x58 [<ffffffff80c7804c>] phy_state_machine+0x48c/0x4f8 [<ffffffff808a1708>] process_one_work+0x158/0x368 [<ffffffff808a1ac0>] worker_thread+0x150/0x4c0 [<ffffffff808a8598>] kthread+0xc8/0xe0 [<ffffffff808617f0>] ret_from_kernel_thread+0x14/0x1c The original motivation for this change originated from Marc Gonzales indicating that his network driver did not have its adjust_link callback executing with phydev->link = 0 while he was expecting it. PHYLIB has never made any such guarantees ever because phy_stop() merely just tells the workqueue to move into PHY_HALTED state which will happen asynchronously. Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Reported-by: David Daney <ddaney.cavm@gmail.com> Fixes: 7ad813f2 ("net: phy: Correctly process PHY_HALTED in phy_stop_machine()") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Eric Dumazet authored
[ Upstream commit 351050ec ] syzkaller had no problem to trigger a deadlock, attaching a KCM socket to another one (or itself). (original syzkaller report was a very confusing lockdep splat during a sendmsg()) It seems KCM claims to only support TCP, but no enforcement is done, so we might need to add additional checks. Fixes: ab7ac4eb ("kcm: Kernel Connection Multiplexor module") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Benjamin Poirier authored
[ Upstream commit edbd58be ] ... which may happen with certain values of tp_reserve and maclen. Fixes: 58d19b19 ("packet: vnet_hdr support for tpacket_rcv") Signed-off-by: Benjamin Poirier <bpoirier@suse.com> Cc: Willem de Bruijn <willemb@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Stefano Brivio authored
[ Upstream commit 0f308686 ] Passing commands for logging to t4_record_mbox() with size MBOX_LEN, when the actual command size is actually smaller, causes out-of-bounds stack accesses in t4_record_mbox() while copying command words here: for (i = 0; i < size / 8; i++) entry->cmd[i] = be64_to_cpu(cmd[i]); Up to 48 bytes from the stack are then leaked to debugfs. This happens whenever we send (and log) commands described by structs fw_sched_cmd (32 bytes leaked), fw_vi_rxmode_cmd (48), fw_hello_cmd (48), fw_bye_cmd (48), fw_initialize_cmd (48), fw_reset_cmd (48), fw_pfvf_cmd (32), fw_eq_eth_cmd (16), fw_eq_ctrl_cmd (32), fw_eq_ofld_cmd (32), fw_acl_mac_cmd(16), fw_rss_glb_config_cmd(32), fw_rss_vi_config_cmd(32), fw_devlog_cmd(32), fw_vi_enable_cmd(48), fw_port_cmd(32), fw_sched_cmd(32), fw_devlog_cmd(32). The cxgb4vf driver got this right instead. When we call t4_record_mbox() to log a command reply, a MBOX_LEN size can be used though, as get_mbox_rpl() will fill cmd_rpl up completely. Fixes: 7f080c3f ("cxgb4: Add support to enable logging of firmware mailbox commands") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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stephen hemminger authored
[ Upstream commit 9b4e946c ] There is a deadlock possible when canceling the link status delayed work queue. The removal process is run with RTNL held, and the link status callback is acquring RTNL. Resolve the issue by using trylock and rescheduling. If cancel is in process, that block it from happening. Fixes: 122a5f64 ("staging: hv: use delayed_work for netvsc_send_garp()") Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Arnd Bergmann authored
[ Upstream commit e58f9583 ] gcc-8.0.0 (snapshot) points out that we copy a variable-length string into a fixed length field using memcpy() with the destination length, and that ends up copying whatever follows the string: inlined from 'ql_core_dump' at drivers/net/ethernet/qlogic/qlge/qlge_dbg.c:1106:2: drivers/net/ethernet/qlogic/qlge/qlge_dbg.c:708:2: error: 'memcpy' reading 15 bytes from a region of size 14 [-Werror=stringop-overflow=] memcpy(seg_hdr->description, desc, (sizeof(seg_hdr->description)) - 1); Changing it to use strncpy() will instead zero-pad the destination, which seems to be the right thing to do here. The bug is probably harmless, but it seems like a good idea to address it in stable kernels as well, if only for the purpose of building with gcc-8 without warnings. Fixes: a61f8026 ("qlge: Add ethtool register dump function.") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Stefano Brivio authored
[ Upstream commit ee6c88bb ] inet_diag_msg_sctp{,l}addr_fill() and sctp_get_sctp_info() copy sizeof(sockaddr_storage) bytes to fill in sockaddr structs used to export diagnostic information to userspace. However, the memory allocated to store sockaddr information is smaller than that and depends on the address family, so we leak up to 100 uninitialized bytes to userspace. Just use the size of the source structs instead, in all the three cases this is what userspace expects. Zero out the remaining memory. Unused bytes (i.e. when IPv4 addresses are used) in source structs sctp_sockaddr_entry and sctp_transport are already cleared by sctp_add_bind_addr() and sctp_transport_new(), respectively. Noticed while testing KASAN-enabled kernel with 'ss': [ 2326.885243] BUG: KASAN: slab-out-of-bounds in inet_sctp_diag_fill+0x42c/0x6c0 [sctp_diag] at addr ffff881be8779800 [ 2326.896800] Read of size 128 by task ss/9527 [ 2326.901564] CPU: 0 PID: 9527 Comm: ss Not tainted 4.11.0-22.el7a.x86_64 #1 [ 2326.909236] Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017 [ 2326.917585] Call Trace: [ 2326.920312] dump_stack+0x63/0x8d [ 2326.924014] kasan_object_err+0x21/0x70 [ 2326.928295] kasan_report+0x288/0x540 [ 2326.932380] ? inet_sctp_diag_fill+0x42c/0x6c0 [sctp_diag] [ 2326.938500] ? skb_put+0x8b/0xd0 [ 2326.942098] ? memset+0x31/0x40 [ 2326.945599] check_memory_region+0x13c/0x1a0 [ 2326.950362] memcpy+0x23/0x50 [ 2326.953669] inet_sctp_diag_fill+0x42c/0x6c0 [sctp_diag] [ 2326.959596] ? inet_diag_msg_sctpasoc_fill+0x460/0x460 [sctp_diag] [ 2326.966495] ? __lock_sock+0x102/0x150 [ 2326.970671] ? sock_def_wakeup+0x60/0x60 [ 2326.975048] ? remove_wait_queue+0xc0/0xc0 [ 2326.979619] sctp_diag_dump+0x44a/0x760 [sctp_diag] [ 2326.985063] ? sctp_ep_dump+0x280/0x280 [sctp_diag] [ 2326.990504] ? memset+0x31/0x40 [ 2326.994007] ? mutex_lock+0x12/0x40 [ 2326.997900] __inet_diag_dump+0x57/0xb0 [inet_diag] [ 2327.003340] ? __sys_sendmsg+0x150/0x150 [ 2327.007715] inet_diag_dump+0x4d/0x80 [inet_diag] [ 2327.012979] netlink_dump+0x1e6/0x490 [ 2327.017064] __netlink_dump_start+0x28e/0x2c0 [ 2327.021924] inet_diag_handler_cmd+0x189/0x1a0 [inet_diag] [ 2327.028045] ? inet_diag_rcv_msg_compat+0x1b0/0x1b0 [inet_diag] [ 2327.034651] ? inet_diag_dump_compat+0x190/0x190 [inet_diag] [ 2327.040965] ? __netlink_lookup+0x1b9/0x260 [ 2327.045631] sock_diag_rcv_msg+0x18b/0x1e0 [ 2327.050199] netlink_rcv_skb+0x14b/0x180 [ 2327.054574] ? sock_diag_bind+0x60/0x60 [ 2327.058850] sock_diag_rcv+0x28/0x40 [ 2327.062837] netlink_unicast+0x2e7/0x3b0 [ 2327.067212] ? netlink_attachskb+0x330/0x330 [ 2327.071975] ? kasan_check_write+0x14/0x20 [ 2327.076544] netlink_sendmsg+0x5be/0x730 [ 2327.080918] ? netlink_unicast+0x3b0/0x3b0 [ 2327.085486] ? kasan_check_write+0x14/0x20 [ 2327.090057] ? selinux_socket_sendmsg+0x24/0x30 [ 2327.095109] ? netlink_unicast+0x3b0/0x3b0 [ 2327.099678] sock_sendmsg+0x74/0x80 [ 2327.103567] ___sys_sendmsg+0x520/0x530 [ 2327.107844] ? __get_locked_pte+0x178/0x200 [ 2327.112510] ? copy_msghdr_from_user+0x270/0x270 [ 2327.117660] ? vm_insert_page+0x360/0x360 [ 2327.122133] ? vm_insert_pfn_prot+0xb4/0x150 [ 2327.126895] ? vm_insert_pfn+0x32/0x40 [ 2327.131077] ? vvar_fault+0x71/0xd0 [ 2327.134968] ? special_mapping_fault+0x69/0x110 [ 2327.140022] ? __do_fault+0x42/0x120 [ 2327.144008] ? __handle_mm_fault+0x1062/0x17a0 [ 2327.148965] ? __fget_light+0xa7/0xc0 [ 2327.153049] __sys_sendmsg+0xcb/0x150 [ 2327.157133] ? __sys_sendmsg+0xcb/0x150 [ 2327.161409] ? SyS_shutdown+0x140/0x140 [ 2327.165688] ? exit_to_usermode_loop+0xd0/0xd0 [ 2327.170646] ? __do_page_fault+0x55d/0x620 [ 2327.175216] ? __sys_sendmsg+0x150/0x150 [ 2327.179591] SyS_sendmsg+0x12/0x20 [ 2327.183384] do_syscall_64+0xe3/0x230 [ 2327.187471] entry_SYSCALL64_slow_path+0x25/0x25 [ 2327.192622] RIP: 0033:0x7f41d18fa3b0 [ 2327.196608] RSP: 002b:00007ffc3b731218 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 2327.205055] RAX: ffffffffffffffda RBX: 00007ffc3b731380 RCX: 00007f41d18fa3b0 [ 2327.213017] RDX: 0000000000000000 RSI: 00007ffc3b731340 RDI: 0000000000000003 [ 2327.220978] RBP: 0000000000000002 R08: 0000000000000004 R09: 0000000000000040 [ 2327.228939] R10: 00007ffc3b730f30 R11: 0000000000000246 R12: 0000000000000003 [ 2327.236901] R13: 00007ffc3b731340 R14: 00007ffc3b7313d0 R15: 0000000000000084 [ 2327.244865] Object at ffff881be87797e0, in cache kmalloc-64 size: 64 [ 2327.251953] Allocated: [ 2327.254581] PID = 9484 [ 2327.257215] save_stack_trace+0x1b/0x20 [ 2327.261485] save_stack+0x46/0xd0 [ 2327.265179] kasan_kmalloc+0xad/0xe0 [ 2327.269165] kmem_cache_alloc_trace+0xe6/0x1d0 [ 2327.274138] sctp_add_bind_addr+0x58/0x180 [sctp] [ 2327.279400] sctp_do_bind+0x208/0x310 [sctp] [ 2327.284176] sctp_bind+0x61/0xa0 [sctp] [ 2327.288455] inet_bind+0x5f/0x3a0 [ 2327.292151] SYSC_bind+0x1a4/0x1e0 [ 2327.295944] SyS_bind+0xe/0x10 [ 2327.299349] do_syscall_64+0xe3/0x230 [ 2327.303433] return_from_SYSCALL_64+0x0/0x6a [ 2327.308194] Freed: [ 2327.310434] PID = 4131 [ 2327.313065] save_stack_trace+0x1b/0x20 [ 2327.317344] save_stack+0x46/0xd0 [ 2327.321040] kasan_slab_free+0x73/0xc0 [ 2327.325220] kfree+0x96/0x1a0 [ 2327.328530] dynamic_kobj_release+0x15/0x40 [ 2327.333195] kobject_release+0x99/0x1e0 [ 2327.337472] kobject_put+0x38/0x70 [ 2327.341266] free_notes_attrs+0x66/0x80 [ 2327.345545] mod_sysfs_teardown+0x1a5/0x270 [ 2327.350211] free_module+0x20/0x2a0 [ 2327.354099] SyS_delete_module+0x2cb/0x2f0 [ 2327.358667] do_syscall_64+0xe3/0x230 [ 2327.362750] return_from_SYSCALL_64+0x0/0x6a [ 2327.367510] Memory state around the buggy address: [ 2327.372855] ffff881be8779700: fc fc fc fc 00 00 00 00 00 00 00 00 fc fc fc fc [ 2327.380914] ffff881be8779780: fb fb fb fb fb fb fb fb fc fc fc fc 00 00 00 00 [ 2327.388972] >ffff881be8779800: 00 00 00 00 fc fc fc fc fb fb fb fb fb fb fb fb [ 2327.397031] ^ [ 2327.401792] ffff881be8779880: fc fc fc fc fb fb fb fb fb fb fb fb fc fc fc fc [ 2327.409850] ffff881be8779900: 00 00 00 00 00 04 fc fc fc fc fc fc 00 00 00 00 [ 2327.417907] ================================================================== This fixes CVE-2017-7558. References: https://bugzilla.redhat.com/show_bug.cgi?id=1480266 Fixes: 8f840e47 ("sctp: add the sctp_diag.c file") Cc: Xin Long <lucien.xin@gmail.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Florian Fainelli authored
[ Upstream commit a1a50c8e ] Junote Cai reported that he was not able to get a DSA setup involving the Freescale DPAA/FMAN driver to work and narrowed it down to of_find_net_device_by_node(). This function requires the network device's device reference to be correctly set which is the case here, though we have lost any device_node association there. The problem is that dpaa_eth_add_device() allocates a "dpaa-ethernet" platform device, and later on dpaa_eth_probe() is called but SET_NETDEV_DEV() won't be propagating &pdev->dev.of_node properly. Fix this by inherenting both the parent device and the of_node when dpaa_eth_add_device() creates the platform device. Fixes: 39339616 ("fsl/fman: Add FMan MAC driver") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Eric Dumazet authored
[ Upstream commit fd6055a8 ] When peeking, if a bad csum is discovered, the skb is unlinked from the queue with __sk_queue_drop_skb and the peek operation restarted. __sk_queue_drop_skb only drops packets that match the queue head. This fails if the skb was found after the head, using SO_PEEK_OFF socket option. This causes an infinite loop. We MUST drop this problematic skb, and we can simply check if skb was already removed by another thread, by looking at skb->next : This pointer is set to NULL by the __skb_unlink() operation, that might have happened only under the spinlock protection. Many thanks to syzkaller team (and particularly Dmitry Vyukov who provided us nice C reproducers exhibiting the lockup) and Willem de Bruijn who provided first version for this patch and a test program. Fixes: 627d2d6b ("udp: enable MSG_PEEK at non-zero offset") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Willem de Bruijn <willemb@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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