kernel/linux.git, branch v4.19.101

Linux 4.19.101

2020-02-01T09:37:12+00:00

KVM: arm64: Write arch.mdcr_el2 changes since last vcpu_load on VHE

2020-02-01T09:37:12+00:00

commit 4942dc6638b07b5326b6d2faa142635c559e7cd5 upstream. On VHE systems arch.mdcr_el2 is written to mdcr_el2 at vcpu_load time to set options for self-hosted debug and the performance monitors extension. Unfortunately the value of arch.mdcr_el2 is not calculated until kvm_arm_setup_debug() in the run loop after the vcpu has been loaded. This means that the initial brief iterations of the run loop use a zero value of mdcr_el2 - until the vcpu is preempted. This also results in a delay between changes to vcpu->guest_debug taking effect. Fix this by writing to mdcr_el2 in kvm_arm_setup_debug() on VHE systems when a change to arch.mdcr_el2 has been detected. Fixes: d5a21bcc2995 ("KVM: arm64: Move common VHE/non-VHE trap config in separate functions") Cc: # 4.17.x- Suggested-by: James Morse Acked-by: Will Deacon Reviewed-by: Marc Zyngier Signed-off-by: Andrew Murray Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

block: fix 32 bit overflow in __blkdev_issue_discard()

2020-02-01T09:37:12+00:00

commit 4800bf7bc8c725e955fcbc6191cc872f43f506d3 upstream. A discard cleanup merged into 4.20-rc2 causes fstests xfs/259 to fall into an endless loop in the discard code. The test is creating a device that is exactly 2^32 sectors in size to test mkfs boundary conditions around the 32 bit sector overflow region. mkfs issues a discard for the entire device size by default, and hence this throws a sector count of 2^32 into blkdev_issue_discard(). It takes the number of sectors to discard as a sector_t - a 64 bit value. The commit ba5d73851e71 ("block: cleanup __blkdev_issue_discard") takes this sector count and casts it to a 32 bit value before comapring it against the maximum allowed discard size the device has. This truncates away the upper 32 bits, and so if the lower 32 bits of the sector count is zero, it starts issuing discards of length 0. This causes the code to fall into an endless loop, issuing a zero length discards over and over again on the same sector. Fixes: ba5d73851e71 ("block: cleanup __blkdev_issue_discard") Tested-by: Darrick J. Wong Reviewed-by: Darrick J. Wong Signed-off-by: Dave Chinner Killed pointless WARN_ON(). Signed-off-by: Jens Axboe Signed-off-by: Konstantin Khlebnikov Signed-off-by: Greg Kroah-Hartman

block: cleanup __blkdev_issue_discard()

2020-02-01T09:37:12+00:00

commit ba5d73851e71847ba7f7f4c27a1a6e1f5ab91c79 upstream. Cleanup __blkdev_issue_discard() a bit: - remove local variable of 'end_sect' - remove code block of 'fail' Cc: Mike Snitzer Cc: Christoph Hellwig Cc: Xiao Ni Cc: Mariusz Dabrowski Tested-by: Rui Salvaterra Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Konstantin Khlebnikov Signed-off-by: Greg Kroah-Hartman

random: try to actively add entropy rather than passively wait for it

2020-02-01T09:37:11+00:00

commit 50ee7529ec4500c88f8664560770a7a1b65db72b upstream. For 5.3 we had to revert a nice ext4 IO pattern improvement, because it caused a bootup regression due to lack of entropy at bootup together with arguably broken user space that was asking for secure random numbers when it really didn't need to. See commit 72dbcf721566 (Revert "ext4: make __ext4_get_inode_loc plug"). This aims to solve the issue by actively generating entropy noise using the CPU cycle counter when waiting for the random number generator to initialize. This only works when you have a high-frequency time stamp counter available, but that's the case on all modern x86 CPU's, and on most other modern CPU's too. What we do is to generate jitter entropy from the CPU cycle counter under a somewhat complex load: calling the scheduler while also guaranteeing a certain amount of timing noise by also triggering a timer. I'm sure we can tweak this, and that people will want to look at other alternatives, but there's been a number of papers written on jitter entropy, and this should really be fairly conservative by crediting one bit of entropy for every timer-induced jump in the cycle counter. Not because the timer itself would be all that unpredictable, but because the interaction between the timer and the loop is going to be. Even if (and perhaps particularly if) the timer actually happens on another CPU, the cacheline interaction between the loop that reads the cycle counter and the timer itself firing is going to add perturbations to the cycle counter values that get mixed into the entropy pool. As Thomas pointed out, with a modern out-of-order CPU, even quite simple loops show a fair amount of hard-to-predict timing variability even in the absense of external interrupts. But this tries to take that further by actually having a fairly complex interaction. This is not going to solve the entropy issue for architectures that have no CPU cycle counter, but it's not clear how (and if) that is solvable, and the hardware in question is largely starting to be irrelevant. And by doing this we can at least avoid some of the even more contentious approaches (like making the entropy waiting time out in order to avoid the possibly unbounded waiting). Cc: Ahmed Darwish Cc: Thomas Gleixner Cc: Theodore Ts'o Cc: Nicholas Mc Guire Cc: Andy Lutomirski Cc: Kees Cook Cc: Willy Tarreau Cc: Alexander E. Patrakov Cc: Lennart Poettering Cc: Noah Meyerhans Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - Use bh_lock_sock in sk_destruct

2020-02-01T09:37:11+00:00

commit 37f96694cf73ba116993a9d2d99ad6a75fa7fdb0 upstream. As af_alg_release_parent may be called from BH context (most notably due to an async request that only completes after socket closure, or as reported here because of an RCU-delayed sk_destruct call), we must use bh_lock_sock instead of lock_sock. Reported-by: syzbot+c2f1558d49e25cc36e5e@syzkaller.appspotmail.com Reported-by: Eric Dumazet Fixes: c840ac6af3f8 ("crypto: af_alg - Disallow bind/setkey/...") Cc: Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

rsi: fix non-atomic allocation in completion handler

2020-02-01T09:37:11+00:00

commit b9b9f9fea21830f85cf0148cd8dce001ae55ead1 upstream. USB completion handlers are called in atomic context and must specifically not allocate memory using GFP_KERNEL. Fixes: a1854fae1414 ("rsi: improve RX packet handling in USB interface") Cc: stable # 4.17 Cc: Prameela Rani Garnepudi Signed-off-by: Johan Hovold Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman

rsi: fix memory leak on failed URB submission

2020-02-01T09:37:11+00:00

commit 47768297481184932844ab01a86752ba31a38861 upstream. Make sure to free the skb on failed receive-URB submission (e.g. on disconnect or currently also due to a missing endpoint). Fixes: a1854fae1414 ("rsi: improve RX packet handling in USB interface") Cc: stable # 4.17 Cc: Prameela Rani Garnepudi Signed-off-by: Johan Hovold Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman

rsi: fix use-after-free on probe errors

2020-02-01T09:37:11+00:00

commit 92aafe77123ab478e5f5095878856ab0424910da upstream. The driver would fail to stop the command timer in most error paths, something which specifically could lead to the timer being freed while still active on I/O errors during probe. Fix this by making sure that each function starting the timer also stops it in all relevant error paths. Reported-by: syzbot+1d1597a5aa3679c65b9f@syzkaller.appspotmail.com Fixes: b78e91bcfb33 ("rsi: Add new firmware loading method") Cc: stable # 4.12 Cc: Prameela Rani Garnepudi Cc: Amitkumar Karwar Signed-off-by: Johan Hovold Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman

sched/fair: Fix insertion in rq->leaf_cfs_rq_list

2020-02-01T09:37:10+00:00

commit f6783319737f28e4436a69611853a5a098cbe974 upstream. Sargun reported a crash: "I picked up c40f7d74c741a907cfaeb73a7697081881c497d0 sched/fair: Fix infinite loop in update_blocked_averages() by reverting a9e7f6544b9c and put it on top of 4.19.13. In addition to this, I uninlined list_add_leaf_cfs_rq for debugging. This revealed a new bug that we didn't get to because we kept getting crashes from the previous issue. When we are running with cgroups that are rapidly changing, with CFS bandwidth control, and in addition using the cpusets cgroup, we see this crash. Specifically, it seems to occur with cgroups that are throttled and we change the allowed cpuset." The algorithm used to order cfs_rq in rq->leaf_cfs_rq_list assumes that it will walk down to root the 1st time a cfs_rq is used and we will finish to add either a cfs_rq without parent or a cfs_rq with a parent that is already on the list. But this is not always true in presence of throttling. Because a cfs_rq can be throttled even if it has never been used but other CPUs of the cgroup have already used all the bandwdith, we are not sure to go down to the root and add all cfs_rq in the list. Ensure that all cfs_rq will be added in the list even if they are throttled. [ mingo: Fix !CGROUPS build. ] Reported-by: Sargun Dhillon Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: tj@kernel.org Fixes: 9c2791f936ef ("Fix hierarchical order in rq->leaf_cfs_rq_list") Link: https://lkml.kernel.org/r/1548825767-10799-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar Cc: Janne Huttunen Signed-off-by: Greg Kroah-Hartman