October 2024 - Linux-stable-mirror

[PATCH v3 2/9] serial: qcom-geni: revert broken hibernation support

by Johan Hovold

This reverts commit 35781d8356a2eecaa6074ceeb80ee22e252fcdae. Hibernation is not supported on Qualcomm platforms with mainline kernels yet a broken vendor implementation for the GENI serial driver made it upstream. This is effectively dead code that cannot be tested and should just be removed, but if these paths were ever hit for an open non-console port they would crash the machine as the driver would fail to enable clocks during restore() (i.e. all ports would have to be closed by drivers and user space before hibernating the system to avoid this as a comment in the code hinted at). The broken implementation also added a random call to enable the receiver in the port setup code where it does not belong and which enables the receiver prematurely for console ports. Fixes: 35781d8356a2 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature") Cc: stable(a)vger.kernel.org # 6.2 Cc: Aniket Randive <quic_arandive(a)quicinc.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 41 ++------------------------- 1 file changed, 2 insertions(+), 39 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index c237c9d107cd..2e4a5361f137 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1170,7 +1170,6 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) false, true, true); geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2); geni_se_select_mode(&port->se, port->dev_data->mode); - qcom_geni_serial_start_rx(uport); port->setup = true; return 0; @@ -1799,38 +1798,6 @@ static int qcom_geni_serial_sys_resume(struct device *dev) return ret; } -static int qcom_geni_serial_sys_hib_resume(struct device *dev) -{ - int ret = 0; - struct uart_port *uport; - struct qcom_geni_private_data *private_data; - struct qcom_geni_serial_port *port = dev_get_drvdata(dev); - - uport = &port->uport; - private_data = uport->private_data; - - if (uart_console(uport)) { - geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS); - geni_icc_set_bw(&port->se); - ret = uart_resume_port(private_data->drv, uport); - /* - * For hibernation usecase clients for - * console UART won't call port setup during restore, - * hence call port setup for console uart. - */ - qcom_geni_serial_port_setup(uport); - } else { - /* - * Peripheral register settings are lost during hibernation. - * Update setup flag such that port setup happens again - * during next session. Clients of HS-UART will close and - * open the port during hibernation. - */ - port->setup = false; - } - return ret; -} - static const struct qcom_geni_device_data qcom_geni_console_data = { .console = true, .mode = GENI_SE_FIFO, @@ -1842,12 +1809,8 @@ static const struct qcom_geni_device_data qcom_geni_uart_data = { }; static const struct dev_pm_ops qcom_geni_serial_pm_ops = { - .suspend = pm_sleep_ptr(qcom_geni_serial_sys_suspend), - .resume = pm_sleep_ptr(qcom_geni_serial_sys_resume), - .freeze = pm_sleep_ptr(qcom_geni_serial_sys_suspend), - .poweroff = pm_sleep_ptr(qcom_geni_serial_sys_suspend), - .restore = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume), - .thaw = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume), + SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend, + qcom_geni_serial_sys_resume) }; static const struct of_device_id qcom_geni_serial_match_table[] = { -- 2.45.2

8 months, 3 weeks

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[PATCH] mm/mremap: Fix move_normal_pmd/retract_page_tables race

by Jann Horn

In mremap(), move_page_tables() looks at the type of the PMD entry and the specified address range to figure out by which method the next chunk of page table entries should be moved. At that point, the mmap_lock is held in write mode, but no rmap locks are held yet. For PMD entries that point to page tables and are fully covered by the source address range, move_pgt_entry(NORMAL_PMD, ...) is called, which first takes rmap locks, then does move_normal_pmd(). move_normal_pmd() takes the necessary page table locks at source and destination, then moves an entire page table from the source to the destination. The problem is: The rmap locks, which protect against concurrent page table removal by retract_page_tables() in the THP code, are only taken after the PMD entry has been read and it has been decided how to move it. So we can race as follows (with two processes that have mappings of the same tmpfs file that is stored on a tmpfs mount with huge=advise); note that process A accesses page tables through the MM while process B does it through the file rmap: process A process B ========= ========= mremap mremap_to move_vma move_page_tables get_old_pmd alloc_new_pmd *** PREEMPT *** madvise(MADV_COLLAPSE) do_madvise madvise_walk_vmas madvise_vma_behavior madvise_collapse hpage_collapse_scan_file collapse_file retract_page_tables i_mmap_lock_read(mapping) pmdp_collapse_flush i_mmap_unlock_read(mapping) move_pgt_entry(NORMAL_PMD, ...) take_rmap_locks move_normal_pmd drop_rmap_locks When this happens, move_normal_pmd() can end up creating bogus PMD entries in the line `pmd_populate(mm, new_pmd, pmd_pgtable(pmd))`. The effect depends on arch-specific and machine-specific details; on x86, you can end up with physical page 0 mapped as a page table, which is likely exploitable for user->kernel privilege escalation. Fix the race by letting process B recheck that the PMD still points to a page table after the rmap locks have been taken. Otherwise, we bail and let the caller fall back to the PTE-level copying path, which will then bail immediately at the pmd_none() check. Bug reachability: Reaching this bug requires that you can create shmem/file THP mappings - anonymous THP uses different code that doesn't zap stuff under rmap locks. File THP is gated on an experimental config flag (CONFIG_READ_ONLY_THP_FOR_FS), so on normal distro kernels you need shmem THP to hit this bug. As far as I know, getting shmem THP normally requires that you can mount your own tmpfs with the right mount flags, which would require creating your own user+mount namespace; though I don't know if some distros maybe enable shmem THP by default or something like that. Bug impact: This issue can likely be used for user->kernel privilege escalation when it is reachable. Cc: stable(a)vger.kernel.org Fixes: 1d65b771bc08 ("mm/khugepaged: retract_page_tables() without mmap or vma lock") Closes: https://project-zero.issues.chromium.org/371047675 Co-developed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Jann Horn <jannh(a)google.com> --- @David: please confirm we can add your Signed-off-by to this patch after the Co-developed-by. (Context: David basically wrote the entire patch except for the commit message.) @akpm: This replaces the previous "[PATCH] mm/mremap: Prevent racing change of old pmd type". --- mm/mremap.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 24712f8dbb6b..dda09e957a5d 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -238,6 +238,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, { spinlock_t *old_ptl, *new_ptl; struct mm_struct *mm = vma->vm_mm; + bool res = false; pmd_t pmd; if (!arch_supports_page_table_move()) @@ -277,19 +278,25 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, if (new_ptl != old_ptl) spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); - /* Clear the pmd */ pmd = *old_pmd; + + /* Racing with collapse? */ + if (unlikely(!pmd_present(pmd) || pmd_leaf(pmd))) + goto out_unlock; + /* Clear the pmd */ pmd_clear(old_pmd); + res = true; VM_BUG_ON(!pmd_none(*new_pmd)); pmd_populate(mm, new_pmd, pmd_pgtable(pmd)); flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE); +out_unlock: if (new_ptl != old_ptl) spin_unlock(new_ptl); spin_unlock(old_ptl); - return true; + return res; } #else static inline bool move_normal_pmd(struct vm_area_struct *vma, --- base-commit: 8cf0b93919e13d1e8d4466eb4080a4c4d9d66d7b change-id: 20241007-move_normal_pmd-vs-collapse-fix-2-387e9a68c7d6 -- Jann Horn <jannh(a)google.com>

8 months, 3 weeks

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[PATCH v2] ata: libata: avoid superfluous disk spin down + spin up during hibernation

by Niklas Cassel

A user reported that commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop") introduced a spin down + immediate spin up of the disk both when entering and when resuming from hibernation. This behavior was not there before, and causes an increased latency both when when entering and when resuming from hibernation. Hibernation is done by three consecutive PM events, in the following order: 1) PM_EVENT_FREEZE 2) PM_EVENT_THAW 3) PM_EVENT_HIBERNATE Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop") modified ata_eh_handle_port_suspend() to call ata_dev_power_set_standby() (which spins down the disk), for both event PM_EVENT_FREEZE and event PM_EVENT_HIBERNATE. Documentation/driver-api/pm/devices.rst, section "Entering Hibernation", explicitly mentions that PM_EVENT_FREEZE does not have to be put the device in a low-power state, and actually recommends not doing so. Thus, let's not spin down the disk on PM_EVENT_FREEZE. (The disk will instead be spun down during the subsequent PM_EVENT_HIBERNATE event.) This way, PM_EVENT_FREEZE will behave as it did before commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop"), while PM_EVENT_HIBERNATE will continue to spin down the disk. This will avoid the superfluous spin down + spin up when entering and resuming from hibernation, while still making sure that the disk is spun down before actually entering hibernation. Cc: stable(a)vger.kernel.org # v6.6+ Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop") Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- Changes since v1: -Add stable to cc. drivers/ata/libata-eh.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 3f0144e7dc80..fa41ea57a978 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -4099,10 +4099,20 @@ static void ata_eh_handle_port_suspend(struct ata_port *ap) WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED); - /* Set all devices attached to the port in standby mode */ - ata_for_each_link(link, ap, HOST_FIRST) { - ata_for_each_dev(dev, link, ENABLED) - ata_dev_power_set_standby(dev); + /* + * We will reach this point for all of the PM events: + * PM_EVENT_SUSPEND (if runtime pm, PM_EVENT_AUTO will also be set) + * PM_EVENT_FREEZE, and PM_EVENT_HIBERNATE. + * + * We do not want to perform disk spin down for PM_EVENT_FREEZE. + * (Spin down will be performed by the subsequent PM_EVENT_HIBERNATE.) + */ + if (!(ap->pm_mesg.event & PM_EVENT_FREEZE)) { + /* Set all devices attached to the port in standby mode */ + ata_for_each_link(link, ap, HOST_FIRST) { + ata_for_each_dev(dev, link, ENABLED) + ata_dev_power_set_standby(dev); + } } /* -- 2.46.2

8 months, 3 weeks

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[PATCH v2 4/7] serial: qcom-geni: fix receiver enable

by Johan Hovold

The receiver should be enabled in the startup() callback and there is no need to stop it on every termios update. Since commit 6f3c3cafb115 ("serial: qcom-geni: disable interrupts during console writes") the calls to manipulate the secondary interrupts, which were done without holding the port lock, can lead to the receiver being left disabled when set_termios() races with the console code (e.g. when init opens the tty during boot). The calls to stop and start rx in set_termios() can similarly race with DMA completion and, for example, cause the DMA buffer to be unmapped twice or the mapping to be leaked. Fixes: 6f3c3cafb115 ("serial: qcom-geni: disable interrupts during console writes") Fixes: 2aaa43c70778 ("tty: serial: qcom-geni-serial: add support for serial engine DMA") Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable(a)vger.kernel.org # 6.3 Cc: Bartosz Golaszewski <bartosz.golaszewski(a)linaro.org> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index dea688db0d7c..5b6c5388efee 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1179,6 +1179,11 @@ static int qcom_geni_serial_startup(struct uart_port *uport) if (ret) return ret; } + + uart_port_lock_irq(uport); + qcom_geni_serial_start_rx(uport); + uart_port_unlock_irq(uport); + enable_irq(uport->irq); return 0; @@ -1264,7 +1269,6 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, unsigned int avg_bw_core; unsigned long timeout; - qcom_geni_serial_stop_rx(uport); /* baud rate */ baud = uart_get_baud_rate(uport, termios, old, 300, 4000000); @@ -1280,7 +1284,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, dev_err(port->se.dev, "Couldn't find suitable clock rate for %u\n", baud * sampling_rate); - goto out_restart_rx; + return; } dev_dbg(port->se.dev, "desired_rate = %u, clk_rate = %lu, clk_div = %u\n", @@ -1371,8 +1375,6 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN); writel(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG); writel(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG); -out_restart_rx: - qcom_geni_serial_start_rx(uport); } #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE -- 2.45.2

8 months, 3 weeks

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[PATCH v2 1/7] serial: qcom-geni: fix premature receiver enable

by Johan Hovold

The receiver should not be enabled until the port is opened so drop the bogus call to start rx from the setup code which is shared with the console implementation. This was added for some confused implementation of hibernation support, but the receiver must not be started unconditionally as the port may not have been open when hibernating the system. Fixes: 35781d8356a2 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature") Cc: stable(a)vger.kernel.org # 6.2 Cc: Aniket Randive <quic_arandive(a)quicinc.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6f0db310cf69..9ea6bd09e665 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1152,7 +1152,6 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) false, true, true); geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2); geni_se_select_mode(&port->se, port->dev_data->mode); - qcom_geni_serial_start_rx(uport); port->setup = true; return 0; -- 2.45.2

8 months, 3 weeks

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[PATCH v2] drm/amdgpu: prevent BO_HANDLES error from being overwritten

by Mohammed Anees

Before this patch, if multiple BO_HANDLES chunks were submitted, the error -EINVAL would be correctly set but could be overwritten by the return value from amdgpu_cs_p1_bo_handles(). This patch ensures that if there are multiple BO_HANDLES, we stop. Cc: stable(a)vger.kernel.org Fixes: fec5f8e8c6bc ("drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit") Signed-off-by: Mohammed Anees <pvmohammedanees2003(a)gmail.com> --- v2: - Switched to goto free_partial_kdata for error handling, following the existing pattern. --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 1e475eb01417..d891ab779ca7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -265,7 +265,7 @@ static int amdgpu_cs_pass1(struct amdgpu_cs_parser *p, /* Only a single BO list is allowed to simplify handling. */ if (p->bo_list) - ret = -EINVAL; + goto free_partial_kdata; ret = amdgpu_cs_p1_bo_handles(p, p->chunks[i].kdata); if (ret) -- 2.46.0

8 months, 3 weeks

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[PATCH v5.10-v5.4] btrfs: get rid of warning on transaction commit when using flushoncommit

by hsimeliere.opensource＠witekio.com

From: Filipe Manana <fdmanana(a)suse.com> commit a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa upstream. When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in which case we would end up starting all delalloc with filemap_fdatawrite_wbc() and not with an async flush via filemap_flush() - that is only possible after the rather recent commit e076ab2a2ca70a ("btrfs: shrink delalloc pages instead of full inodes"). However that creates a whole new can of worms due to new lock dependencies, which lockdep complains, like for example: [ 8948.247280] ====================================================== [ 8948.247823] WARNING: possible circular locking dependency detected [ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted [ 8948.248786] ------------------------------------------------------ [ 8948.249320] kworker/u16:18/933570 is trying to acquire lock: [ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs] [ 8948.250638] but task is already holding lock: [ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.252018] which lock already depends on the new lock. [ 8948.252710] the existing dependency chain (in reverse order) is: [ 8948.253343] -> #2 (&root->delalloc_mutex){+.+.}-{3:3}: [ 8948.253950] __mutex_lock+0x90/0x900 [ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs] [ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs] [ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs] [ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs] [ 8948.258418] __x64_sys_ioctl+0x83/0xb0 [ 8948.258793] do_syscall_64+0x3b/0xc0 [ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.259709] -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}: [ 8948.260330] __mutex_lock+0x90/0x900 [ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs] [ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs] [ 8948.262909] open_ctree+0x1511/0x171e [btrfs] [ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 8948.263863] legacy_get_tree+0x30/0x50 [ 8948.264242] vfs_get_tree+0x28/0xc0 [ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0 [ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs] [ 8948.265462] legacy_get_tree+0x30/0x50 [ 8948.265851] vfs_get_tree+0x28/0xc0 [ 8948.266203] path_mount+0x2d4/0xbe0 [ 8948.266554] __x64_sys_mount+0x103/0x140 [ 8948.266940] do_syscall_64+0x3b/0xc0 [ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.267790] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 8948.268322] __lock_acquire+0x12e8/0x2260 [ 8948.268733] lock_acquire+0xd7/0x310 [ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.270588] cow_file_range+0x17e/0x490 [btrfs] [ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.273113] extent_writepages+0x76/0x130 [btrfs] [ 8948.273573] do_writepages+0xd2/0x1c0 [ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.275417] flush_space+0x1f2/0x630 [btrfs] [ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.276438] process_one_work+0x252/0x5a0 [ 8948.276829] worker_thread+0x55/0x3b0 [ 8948.277189] kthread+0xf2/0x120 [ 8948.277506] ret_from_fork+0x22/0x30 [ 8948.277868] other info that might help us debug this: [ 8948.278548] Chain exists of: sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex [ 8948.279601] Possible unsafe locking scenario: [ 8948.280102] CPU0 CPU1 [ 8948.280508] ---- ---- [ 8948.280915] lock(&root->delalloc_mutex); [ 8948.281271] lock(&fs_info->delalloc_root_mutex); [ 8948.281915] lock(&root->delalloc_mutex); [ 8948.282487] lock(sb_internal#2); [ 8948.282800] *** DEADLOCK *** [ 8948.283333] 4 locks held by kworker/u16:18/933570: [ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.287596] stack backtrace: [ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1 [ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [ 8948.290298] Call Trace: [ 8948.290517] <TASK> [ 8948.290700] dump_stack_lvl+0x59/0x73 [ 8948.291026] check_noncircular+0xf3/0x110 [ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs] [ 8948.291826] __lock_acquire+0x12e8/0x2260 [ 8948.292241] lock_acquire+0xd7/0x310 [ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.293241] ? lock_is_held_type+0xea/0x140 [ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294957] ? _raw_spin_unlock+0x29/0x40 [ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs] [ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.296270] cow_file_range+0x17e/0x490 [btrfs] [ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs] [ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.299061] extent_writepages+0x76/0x130 [btrfs] [ 8948.299495] do_writepages+0xd2/0x1c0 [ 8948.299817] ? sched_clock_cpu+0xd/0x110 [ 8948.300160] ? lock_release+0x155/0x4a0 [ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0 [ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.301706] ? lock_release+0x155/0x4a0 [ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.302564] flush_space+0x1f2/0x630 [btrfs] [ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.303510] process_one_work+0x252/0x5a0 [ 8948.303860] ? process_one_work+0x5a0/0x5a0 [ 8948.304221] worker_thread+0x55/0x3b0 [ 8948.304543] ? process_one_work+0x5a0/0x5a0 [ 8948.304904] kthread+0xf2/0x120 [ 8948.305184] ? kthread_complete_and_exit+0x20/0x20 [ 8948.305598] ret_from_fork+0x22/0x30 [ 8948.305921] </TASK> It all comes from the fact that btrfs_start_delalloc_roots() takes the delalloc_root_mutex, in the transaction commit path we are holding a read lock on one of the superblock's freeze semaphores (via sb_start_intwrite()), the async reclaim task can also do a call to btrfs_start_delalloc_roots(), which ends up triggering writeback with calls to filemap_fdatawrite_wbc(), resulting in extent allocation which in turn can call btrfs_start_transaction(), which will result in taking the freeze semaphore via sb_start_intwrite(), forming a nasty dependency on all those locks which can be taken in different orders by different code paths. So just adopt the simple approach of calling try_to_writeback_inodes_sb() at btrfs_start_delalloc_flush(). Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/ Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gm… Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gm… Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/ Reviewed-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> [ add more link reports ] Signed-off-by: David Sterba <dsterba(a)suse.com> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource(a)witekio.com> --- fs/btrfs/transaction.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8878aa7cbdc5..c797563fa9cf 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2021,16 +2021,24 @@ static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans) struct btrfs_fs_info *fs_info = trans->fs_info; /* - * We use writeback_inodes_sb here because if we used + * We use try_to_writeback_inodes_sb() here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { - writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); } else { struct btrfs_pending_snapshot *pending; struct list_head *head = &trans->transaction->pending_snapshots; -- 2.43.0

8 months, 3 weeks

3
3
0 0

[PATCH] Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails

by libo.chen.cn＠windriver.com

From: Rick Edgecombe <rick.p.edgecombe(a)intel.com> commit 03f5a999adba ("Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails") In CoCo VMs it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. VMBus code could free decrypted pages if set_memory_encrypted()/decrypted() fails. Leak the pages if this happens. Signed-off-by: Rick Edgecombe <rick.p.edgecombe(a)intel.com> Signed-off-by: Michael Kelley <mhklinux(a)outlook.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy(a)linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Link: https://lore.kernel.org/r/20240311161558.1310-2-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu(a)kernel.org> Message-ID: <20240311161558.1310-2-mhklinux(a)outlook.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> CVE-2024-36913 Signed-off-by: Libo Chen <libo.chen.cn(a)windriver.com> --- This commit is backporting 03f5a999adba to the branch linux-5.15.y to solve the CVE-2024-36913. Please merge this commit to linux-5.15.y. drivers/hv/connection.c | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 47fb412eafd3..8283e7ba156e 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -19,6 +19,7 @@ #include <linux/vmalloc.h> #include <linux/hyperv.h> #include <linux/export.h> +#include <linux/set_memory.h> #include <asm/mshyperv.h> #include "hyperv_vmbus.h" @@ -216,6 +217,29 @@ int vmbus_connect(void) goto cleanup; } + ret = set_memory_decrypted((unsigned long) + vmbus_connection.monitor_pages[0], 1); + ret |= set_memory_decrypted((unsigned long) + vmbus_connection.monitor_pages[1], 1); + if (ret) { + /* + * If set_memory_decrypted() fails, the encryption state + * of the memory is unknown. So leak the memory instead + * of risking returning decrypted memory to the free list. + * For simplicity, always handle both pages the same. + */ + vmbus_connection.monitor_pages[0] = NULL; + vmbus_connection.monitor_pages[1] = NULL; + goto cleanup; + } + + /* + * Set_memory_decrypted() will change the memory contents if + * decryption occurs, so zero monitor pages here. + */ + memset(vmbus_connection.monitor_pages[0], 0x00, HV_HYP_PAGE_SIZE); + memset(vmbus_connection.monitor_pages[1], 0x00, HV_HYP_PAGE_SIZE); + msginfo = kzalloc(sizeof(*msginfo) + sizeof(struct vmbus_channel_initiate_contact), GFP_KERNEL); @@ -303,10 +327,19 @@ void vmbus_disconnect(void) vmbus_connection.int_page = NULL; } - hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[0]); - hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[1]); - vmbus_connection.monitor_pages[0] = NULL; - vmbus_connection.monitor_pages[1] = NULL; + if (vmbus_connection.monitor_pages[0]) { + if (!set_memory_encrypted( + (unsigned long)vmbus_connection.monitor_pages[0], 1)) + hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[0]); + vmbus_connection.monitor_pages[0] = NULL; + } + + if (vmbus_connection.monitor_pages[1]) { + if (!set_memory_encrypted( + (unsigned long)vmbus_connection.monitor_pages[1], 1)) + hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[1]); + vmbus_connection.monitor_pages[1] = NULL; + } } /* -- 2.25.1

8 months, 3 weeks

2
1
0 0

[PATCH v3 net 0/3] net: enetc: fix some issues of XDP

by Wei Fang

We found some bugs when testing the XDP function of enetc driver, and these bugs are easy to reproduce. This is not only causes XDP to not work, but also the network cannot be restored after exiting the XDP program. So the patch set is mainly to fix these bugs. For details, please see the commit message of each patch. --- v1 link: https://lore.kernel.org/bpf/20240919084104.661180-1-wei.fang@nxp.com/T/ v2 link: https://lore.kernel.org/netdev/20241008224806.2onzkt3gbslw5jxb@skbuf/T/ --- Wei Fang (3): net: enetc: remove xdp_drops statistic from enetc_xdp_drop() net: enetc: fix the issues of XDP_REDIRECT feature net: enetc: disable IRQ after Rx and Tx BD rings are disabled drivers/net/ethernet/freescale/enetc/enetc.c | 56 +++++++++++++++----- drivers/net/ethernet/freescale/enetc/enetc.h | 1 + 2 files changed, 44 insertions(+), 13 deletions(-) -- 2.34.1

8 months, 3 weeks

2
8
0 0

[PATCH] x86/stackprotector: Work around strict Clang TLS symbol requirements

by Ard Biesheuvel

From: Ard Biesheuvel <ardb(a)kernel.org> GCC and Clang both implement stack protector support based on Thread Local Storage (TLS) variables, and this is used in the kernel to implement per-task stack cookies, by copying a task's stack cookie into a per-CPU variable every time it is scheduled in. Both now also implement -mstack-protector-guard-symbol=, which permits the TLS variable to be specified directly. This is useful because it will allow us to move away from using a fixed offset of 40 bytes into the per-CPU area on x86_64, which requires a lot of special handling in the per-CPU code and the runtime relocation code. However, while GCC is rather lax in its implementation of this command line option, Clang actually requires that the provided symbol name refers to a TLS variable (i.e., one declared with __thread), although it also permits the variable to be undeclared entirely, in which case it will use an implicit declaration of the right type. The upshot of this is that Clang will emit the correct references to the stack cookie variable in most cases, e.g., 10d: 64 a1 00 00 00 00 mov %fs:0x0,%eax 10f: R_386_32 __stack_chk_guard However, if a non-TLS definition of the symbol in question is visible in the same compilation unit (which amounts to the whole of vmlinux if LTO is enabled), it will drop the per-CPU prefix and emit a load from a bogus address. Work around this by using a symbol name that never occurs in C code, and emit it as an alias in the linker script. Fixes: 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular percpu variable") Cc: <stable(a)vger.kernel.org> Cc: Fangrui Song <i(a)maskray.me> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Uros Bizjak <ubizjak(a)gmail.com> Cc: Nathan Chancellor <nathan(a)kernel.org> Cc: Andy Lutomirski <luto(a)kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1854 Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> --- arch/x86/Makefile | 5 +++-- arch/x86/entry/entry.S | 16 ++++++++++++++++ arch/x86/kernel/cpu/common.c | 2 ++ arch/x86/kernel/vmlinux.lds.S | 3 +++ 4 files changed, 24 insertions(+), 2 deletions(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index cd75e78a06c1..5b773b34768d 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -142,9 +142,10 @@ ifeq ($(CONFIG_X86_32),y) ifeq ($(CONFIG_STACKPROTECTOR),y) ifeq ($(CONFIG_SMP),y) - KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard + KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \ + -mstack-protector-guard-symbol=__ref_stack_chk_guard else - KBUILD_CFLAGS += -mstack-protector-guard=global + KBUILD_CFLAGS += -mstack-protector-guard=global endif endif else diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S index d9feadffa972..a503e6d535f8 100644 --- a/arch/x86/entry/entry.S +++ b/arch/x86/entry/entry.S @@ -46,3 +46,19 @@ EXPORT_SYMBOL_GPL(mds_verw_sel); .popsection THUNK warn_thunk_thunk, __warn_thunk + +#ifndef CONFIG_X86_64 +/* + * Clang's implementation of TLS stack cookies requires the variable in + * question to be a TLS variable. If the variable happens to be defined as an + * ordinary variable with external linkage in the same compilation unit (which + * amounts to the whole of vmlinux with LTO enabled), Clang will drop the + * segment register prefix from the references, resulting in broken code. Work + * around this by avoiding the symbol used in -mstack-protector-guard-symbol= + * entirely in the C code, and use an alias emitted by the linker script + * instead. + */ +#ifdef CONFIG_STACKPROTECTOR +EXPORT_SYMBOL(__ref_stack_chk_guard); +#endif +#endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 07a34d723505..ba83f54dfaa8 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2085,8 +2085,10 @@ void syscall_init(void) #ifdef CONFIG_STACKPROTECTOR DEFINE_PER_CPU(unsigned long, __stack_chk_guard); +#ifndef CONFIG_SMP EXPORT_PER_CPU_SYMBOL(__stack_chk_guard); #endif +#endif #endif /* CONFIG_X86_64 */ diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 2b7c8c14c6fd..a80ad2bf8da4 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -490,6 +490,9 @@ SECTIONS . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE), "kernel image bigger than KERNEL_IMAGE_SIZE"); +/* needed for Clang - see arch/x86/entry/entry.S */ +PROVIDE(__ref_stack_chk_guard = __stack_chk_guard); + #ifdef CONFIG_X86_64 /* * Per-cpu symbols which need to be offset from __per_cpu_load -- 2.46.1.824.gd892dcdcdd-goog

8 months, 3 weeks

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Linux-stable-mirror October 2024