- 14 Apr, 2015 40 commits
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Linus Torvalds authored
commit 690eac53 upstream. Commit fee7e49d ("mm: propagate error from stack expansion even for guard page") made sure that we return the error properly for stack growth conditions. It also theorized that counting the guard page towards the stack limit might break something, but also said "Let's see if anybody notices". Somebody did notice. Apparently android-x86 sets the stack limit very close to the limit indeed, and including the guard page in the rlimit check causes the android 'zygote' process problems. So this adds the (fairly trivial) code to make the stack rlimit check be against the actual real stack size, rather than the size of the vma that includes the guard page. Reported-and-tested-by:
Chih-Wei Huang <cwhuang@android-x86.org> Cc: Jay Foad <jay.foad@gmail.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Zefan Li <lizefan@huawei.com>
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Johan Hovold authored
commit 32a4bf2e upstream. Use tty kref to release the fake tty in usb_console_setup to avoid use after free if the underlying serial driver has acquired a reference. Note that using the tty destructor release_one_tty requires some more state to be initialised. Fixes: 4a90f09b ("tty: usb-serial krefs") Signed-off-by:
Johan Hovold <johan@kernel.org> [lizf: Backported to 3.4: adjust context] Signed-off-by:
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Arseny Solokha authored
commit 56abcab8 upstream. Commit 8dccddbc ("OHCI: final fix for NVIDIA problems (I hope)") introduced into 3.1.9 broke boot on e.g. Freescale P2020DS development board. The code path that was previously specific to NVIDIA controllers had then become taken for all chips. However, the M5237 installed on the board wedges solid when accessing its base+OHCI_FMINTERVAL register, making it impossible to boot any kernel newer than 3.1.8 on this particular and apparently other similar machines. Don't readl() and writel() base+OHCI_FMINTERVAL on PCI ID 10b9:5237. The patch is suitable for the -next tree as well as all maintained kernels up to 3.2 inclusive. Signed-off-by:
Arseny Solokha <asolokha@kb.kras.ru> Acked-by:
Alan Stern <stern@rowland.harvard.edu> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Dan Carpenter authored
commit 606185b2 upstream. This is a static checker fix. We write some binary settings to the sysfs file. One of the settings is the "->startup_profile". There isn't any checking to make sure it fits into the pyra->profile_settings[] array in the profile_activated() function. I added a check to pyra_sysfs_write_settings() in both places because I wasn't positive that the other callers were correct. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
Jiri Kosina <jkosina@suse.cz> [lizf: Backported to 3.4: define the variable @settings] Signed-off-by:
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Johannes Weiner authored
commit 2d6d7f98 upstream. Tejun, while reviewing the code, spotted the following race condition between the dirtying and truncation of a page: __set_page_dirty_nobuffers() __delete_from_page_cache() if (TestSetPageDirty(page)) page->mapping = NULL if (PageDirty()) dec_zone_page_state(page, NR_FILE_DIRTY); dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE); if (page->mapping) account_page_dirtied(page) __inc_zone_page_state(page, NR_FILE_DIRTY); __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE); which results in an imbalance of NR_FILE_DIRTY and BDI_RECLAIMABLE. Dirtiers usually lock out truncation, either by holding the page lock directly, or in case of zap_pte_range(), by pinning the mapcount with the page table lock held. The notable exception to this rule, though, is do_wp_page(), for which this race exists. However, do_wp_page() already waits for a locked page to unlock before setting the dirty bit, in order to prevent a race where clear_page_dirty() misses the page bit in the presence of dirty ptes. Upgrade that wait to a fully locked set_page_dirty() to also cover the situation explained above. Afterwards, the code in set_page_dirty() dealing with a truncation race is no longer needed. Remove it. Reported-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Konstantin Khlebnikov authored
commit 7a3ef208 upstream. Constantly forking task causes unlimited grow of anon_vma chain. Each next child allocates new level of anon_vmas and links vma to all previous levels because pages might be inherited from any level. This patch adds heuristic which decides to reuse existing anon_vma instead of forking new one. It adds counter anon_vma->degree which counts linked vmas and directly descending anon_vmas and reuses anon_vma if counter is lower than two. As a result each anon_vma has either vma or at least two descending anon_vmas. In such trees half of nodes are leafs with alive vmas, thus count of anon_vmas is no more than two times bigger than count of vmas. This heuristic reuses anon_vmas as few as possible because each reuse adds false aliasing among vmas and rmap walker ought to scan more ptes when it searches where page is might be mapped. Link: http://lkml.kernel.org/r/20120816024610.GA5350@evergreen.ssec.wisc.edu Fixes: 5beb4930 ("mm: change anon_vma linking to fix multi-process server scalability issue") [akpm@linux-foundation.org: fix typo, per Rik] Signed-off-by:
Konstantin Khlebnikov <koct9i@gmail.com> Reported-by:
Daniel Forrest <dan.forrest@ssec.wisc.edu> Tested-by:
Michal Hocko <mhocko@suse.cz> Tested-by:
Jerome Marchand <jmarchan@redhat.com> Reviewed-by:
Rik van Riel <riel@redhat.com> Signed-off-by:
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Andreas Müller authored
commit d025933e upstream. As multicast-frames can't be fragmented, "dot11MulticastReceivedFrameCount" stopped being incremented after the use-after-free fix. Furthermore, the RX-LED will be triggered by every multicast frame (which wouldn't happen before) which wouldn't allow the LED to rest at all. Fixes https://bugzilla.kernel.org/show_bug.cgi?id=89431 which also had the patch. Fixes: b8fff407 ("mac80211: fix use-after-free in defragmentation") Signed-off-by:
Andreas Müller <goo@stapelspeicher.org> [rewrite commit message] Signed-off-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
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Dmitry Torokhov authored
commit 9333caea upstream. When KBC is in active multiplexing mode the touchpad on this laptop does not work. Reported-by:
Bilal Koc <koc.bilo@googlemail.com> Signed-off-by:
Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by:
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Srihari Vijayaraghavan authored
commit 148e9a71 upstream. On some laptops, keyboard needs to be reset in order to successfully detect touchpad (e.g., some Gigabyte laptop models with Elantech touchpads). Without resettin keyboard touchpad pretends to be completely dead. Based on the original patch by Mateusz Jończyk this version has been expanded to include DMI based detection & application of the fix automatically on the affected models of laptops. This has been confirmed to fix problem by three users already on three different models of laptops. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81331Signed-off-by:
Srihari Vijayaraghavan <linux.bug.reporting@gmail.com> Acked-by:
Mateusz Jończyk <mat.jonczyk@o2.pl> Tested-by:
Guillaum Bouchard <guillaum.bouchard@gmail.com> Signed-off-by:
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Sasha Levin authored
commit 5e5aeb43 upstream. Verify that the frequency value from userspace is valid and makes sense. Unverified values can cause overflows later on. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:
Sasha Levin <sasha.levin@oracle.com> [jstultz: Fix up bug for negative values and drop redunent cap check] Signed-off-by:
John Stultz <john.stultz@linaro.org> [lizf: Backported to 3.4: adjust context] Signed-off-by:
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Sasha Levin authored
commit 6ada1fc0 upstream. An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Andy Shevchenko authored
commit 4aaa7187 upstream. DMA mapped IO should be unmapped on the error path in probe() and unconditionally on remove(). Fixes: 62936009 ([libata] Add 460EX on-chip SATA driver, sata_dwc_460ex) Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
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Linus Torvalds authored
commit fee7e49d upstream. Jay Foad reports that the address sanitizer test (asan) sometimes gets confused by a stack pointer that ends up being outside the stack vma that is reported by /proc/maps. This happens due to an interaction between RLIMIT_STACK and the guard page: when we do the guard page check, we ignore the potential error from the stack expansion, which effectively results in a missing guard page, since the expected stack expansion won't have been done. And since /proc/maps explicitly ignores the guard page (commit d7824370: "mm: fix up some user-visible effects of the stack guard page"), the stack pointer ends up being outside the reported stack area. This is the minimal patch: it just propagates the error. It also effectively makes the guard page part of the stack limit, which in turn measn that the actual real stack is one page less than the stack limit. Let's see if anybody notices. We could teach acct_stack_growth() to allow an extra page for a grow-up/grow-down stack in the rlimit test, but I don't want to add more complexity if it isn't needed. Reported-and-tested-by:
Jay Foad <jay.foad@gmail.com> Signed-off-by:
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David Peterson authored
commit 1ae78a48 upstream. Added virtual com port VID/PID entries for CEL USB sticks and MeshWorks devices. Signed-off-by:
David Peterson <david.peterson@cel.com> Signed-off-by:
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Michael S. Tsirkin authored
commit a1eb03f5 upstream. The reason we defer kfree until release function is because it's a general rule for kobjects: kfree of the reference counter itself is only legal in the release function. Previous patch didn't make this clear, document this in code. Signed-off-by:
Michael S. Tsirkin <mst@redhat.com> [lizf: Backported to 3.4: adjust filename] Signed-off-by:
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Sasha Levin authored
commit 63bd62a0 upstream. A struct device which has just been unregistered can live on past the point at which a driver decides to drop it's initial reference to the kobject gained on allocation. This implies that when releasing a virtio device, we can't free a struct virtio_device until the underlying struct device has been released, which might not happen immediately on device_unregister(). Unfortunately, this is exactly what virtio pci does: it has an empty release callback, and frees memory immediately after unregistering the device. This causes an easy to reproduce crash if CONFIG_DEBUG_KOBJECT_RELEASE it enabled. To fix, free the memory only once we know the device is gone in the release callback. Signed-off-by:
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Wanlong Gao authored
commit 9bffdca8 upstream. Use dev_to_virtio wrapper in virtio to make code clearly. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by:
Wanlong Gao <gaowanlong@cn.fujitsu.com> Signed-off-by:
Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Takashi Iwai authored
commit c507de88 upstream. stac_store_hints() does utterly wrong for masking the values for gpio_dir and gpio_data, likely due to copy&paste errors. Fortunately, this feature is used very rarely, so the impact must be really small. Reported-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Daniel Borkmann authored
commit b485342b upstream. Commit a074335a ("x86, um: Mark system call tables readonly") was supposed to mark the sys_call_table in UML as RO by adding the const, but it doesn't have the desired effect as it's nevertheless being placed into the data section since __cacheline_aligned enforces sys_call_table being placed into .data..cacheline_aligned instead. We need to use the ____cacheline_aligned version instead to fix this issue. Before: $ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table" U sys_writev 0000000000000000 D sys_call_table 0000000000000000 D syscall_table_size After: $ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table" U sys_writev 0000000000000000 R sys_call_table 0000000000000000 D syscall_table_size Fixes: a074335a ("x86, um: Mark system call tables readonly") Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Daniel Borkmann <dborkman@redhat.com> Signed-off-by:
Richard Weinberger <richard@nod.at> Signed-off-by:
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Preston Fick authored
commit 90441b4d upstream. Fixing typo for MeshConnect IDs. The original PID (0x8875) is not in production and is not needed. Instead it has been changed to the official production PID (0x8857). Signed-off-by:
Preston Fick <pffick@gmail.com> Signed-off-by:
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Tomi Valkeinen authored
commit 92b004d1 upstream. If the probe of an fb driver has been deferred due to missing dependencies, and the probe is later ran when a module is loaded, the fbdev framework will try to find a logo to use. However, the logos are __initdata, and have already been freed. This causes sometimes page faults, if the logo memory is not mapped, sometimes other random crashes as the logo data is invalid, and sometimes nothing, if the fbdev decides to reject the logo (e.g. the random value depicting the logo's height is too big). This patch adds a late_initcall function to mark the logos as freed. In reality the logos are freed later, and fbdev probe may be ran between this late_initcall and the freeing of the logos. In that case we will miss drawing the logo, even if it would be possible. Signed-off-by:
Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by:
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Toshiaki Makita authored
commit 796f2da8 upstream. When vlan tags are stacked, it is very likely that the outer tag is stored in skb->vlan_tci and skb->protocol shows the inner tag's vlan_proto. Currently netif_skb_features() first looks at skb->protocol even if there is the outer tag in vlan_tci, thus it incorrectly retrieves the protocol encapsulated by the inner vlan instead of the inner vlan protocol. This allows GSO packets to be passed to HW and they end up being corrupted. Fixes: 58e998c6 ("offloading: Force software GSO for multiple vlan tags.") Signed-off-by:
Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by:
David S. Miller <davem@davemloft.net> [lizf: Backported to 3.4: - remove ETH_P_8021AD - pass protocol to harmonize_features()] Signed-off-by:
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Rabin Vincent authored
commit 7e77bdeb upstream. If a request is backlogged, it's complete() handler will get called twice: once with -EINPROGRESS, and once with the final error code. af_alg's complete handler, unlike other users, does not handle the -EINPROGRESS but instead always completes the completion that recvmsg() is waiting on. This can lead to a return to user space while the request is still pending in the driver. If userspace closes the sockets before the requests are handled by the driver, this will lead to use-after-frees (and potential crashes) in the kernel due to the tfm having been freed. The crashes can be easily reproduced (for example) by reducing the max queue length in cryptod.c and running the following (from http://www.chronox.de/libkcapi.html) on AES-NI capable hardware: $ while true; do kcapi -x 1 -e -c '__ecb-aes-aesni' \ -k 00000000000000000000000000000000 \ -p 00000000000000000000000000000000 >/dev/null & done Signed-off-by:
Rabin Vincent <rabin.vincent@axis.com> Signed-off-by:
Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Jan Kara authored
commit e237ec37 upstream. Check that length specified in a component of a symlink fits in the input buffer we are reading. Also properly ignore component length for component types that do not use it. Otherwise we read memory after end of buffer for corrupted udf image. Reported-by:
Carl Henrik Lunde <chlunde@ping.uio.no> Signed-off-by:
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Andy Lutomirski authored
commit 394f56fe upstream. The theory behind vdso randomization is that it's mapped at a random offset above the top of the stack. To avoid wasting a page of memory for an extra page table, the vdso isn't supposed to extend past the lowest PMD into which it can fit. Other than that, the address should be a uniformly distributed address that meets all of the alignment requirements. The current algorithm is buggy: the vdso has about a 50% probability of being at the very end of a PMD. The current algorithm also has a decent chance of failing outright due to incorrect handling of the case where the top of the stack is near the top of its PMD. This fixes the implementation. The paxtest estimate of vdso "randomisation" improves from 11 bits to 18 bits. (Disclaimer: I don't know what the paxtest code is actually calculating.) It's worth noting that this algorithm is inherently biased: the vdso is more likely to end up near the end of its PMD than near the beginning. Ideally we would either nix the PMD sharing requirement or jointly randomize the vdso and the stack to reduce the bias. In the mean time, this is a considerable improvement with basically no risk of compatibility issues, since the allowed outputs of the algorithm are unchanged. As an easy test, doing this: for i in `seq 10000` do grep -P vdso /proc/self/maps |cut -d- -f1 done |sort |uniq -d used to produce lots of output (1445 lines on my most recent run). A tiny subset looks like this: 7fffdfffe000 7fffe01fe000 7fffe05fe000 7fffe07fe000 7fffe09fe000 7fffe0bfe000 7fffe0dfe000 Note the suspicious fe000 endings. With the fix, I get a much more palatable 76 repeated addresses. Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
Andy Lutomirski <luto@amacapital.net> [lizf: Backported to 3.4: - adjust context - adjust comment] Signed-off-by:
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Jan Kara authored
commit 0e5cc9a4 upstream. Symlink reading code does not check whether the resulting path fits into the page provided by the generic code. This isn't as easy as just checking the symlink size because of various encoding conversions we perform on path. So we have to check whether there is still enough space in the buffer on the fly. Reported-by:
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Jan Kara authored
commit a1d47b26 upstream. UDF specification allows arbitrarily large symlinks. However we support only symlinks at most one block large. Check the length of the symlink so that we don't access memory beyond end of the symlink block. Reported-by:
Carl Henrik Lunde <chlunde@gmail.com> Signed-off-by:
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Jan Kara authored
commit e159332b upstream. Verify that inode size is sane when loading inode with data stored in ICB. Otherwise we may get confused later when working with the inode and inode size is too big. Reported-by:
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Jan Kara authored
commit 4e202462 upstream. We didn't check length of rock ridge ER records before printing them. Thus corrupted isofs image can cause us to access and print some memory behind the buffer with obvious consequences. Reported-and-tested-by:
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Junxiao Bi authored
commit 136f49b9 upstream. For buffer write, page lock will be got in write_begin and released in write_end, in ocfs2_write_end_nolock(), before it unlock the page in ocfs2_free_write_ctxt(), it calls ocfs2_run_deallocs(), this will ask for the read lock of journal->j_trans_barrier. Holding page lock and ask for journal->j_trans_barrier breaks the locking order. This will cause a deadlock with journal commit threads, ocfs2cmt will get write lock of journal->j_trans_barrier first, then it wakes up kjournald2 to do the commit work, at last it waits until done. To commit journal, kjournald2 needs flushing data first, it needs get the cache page lock. Since some ocfs2 cluster locks are holding by write process, this deadlock may hung the whole cluster. unlock pages before ocfs2_run_deallocs() can fix the locking order, also put unlock before ocfs2_commit_trans() to make page lock is unlocked before j_trans_barrier to preserve unlocking order. Signed-off-by:
Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by:
Wengang Wang <wen.gang.wang@oracle.com> Reviewed-by:
Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
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Jiri Jaburek authored
commit d70a1b98 upstream. The Arcam rPAC seems to have the same problem - whenever anything (alsamixer, udevd, 3.9+ kernel from 60af3d03, ..) attempts to access mixer / control interface of the card, the firmware "locks up" the entire device, resulting in SNDRV_PCM_IOCTL_HW_PARAMS failed (-5): Input/output error from alsa-lib. Other operating systems can somehow read the mixer (there seems to be playback volume/mute), but any manipulation is ignored by the device (which has hardware volume controls). Signed-off-by:
Jiri Jaburek <jjaburek@redhat.com> Signed-off-by:
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Nicholas Bellinger authored
commit 6bf6ca75 upstream. This patch changes iscsit_do_tx_data() to fail on short writes when kernel_sendmsg() returns a value different than requested transfer length, returning -EPIPE and thus causing a connection reset to occur. This avoids a potential bug in the original code where a short write would result in kernel_sendmsg() being called again with the original iovec base + length. In practice this has not been an issue because iscsit_do_tx_data() is only used for transferring 48 byte headers + 4 byte digests, along with seldom used control payloads from NOPIN + TEXT_RSP + REJECT with less than 32k of data. So following Al's audit of iovec consumers, go ahead and fail the connection on short writes for now, and remove the bogus logic ahead of his proper upstream fix. Reported-by:
Al Viro <viro@zeniv.linux.org.uk> Cc: David S. Miller <davem@davemloft.net> Signed-off-by:
Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by:
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Jan Kara authored
commit f54e18f1 upstream. Rock Ridge extensions define so called Continuation Entries (CE) which define where is further space with Rock Ridge data. Corrupted isofs image can contain arbitrarily long chain of these, including a one containing loop and thus causing kernel to end in an infinite loop when traversing these entries. Limit the traversal to 32 entries which should be more than enough space to store all the Rock Ridge data. Reported-by:
P J P <ppandit@redhat.com> Signed-off-by:
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Long Li authored
commit e86fb5e8 upstream. When ring buffer returns an error indicating retry, storvsc may not return a proper error code to SCSI when bounce buffer is not used. This has introduced I/O freeze on RAID running atop storvsc devices. This patch fixes it by always returning a proper error code. Signed-off-by:
Long Li <longli@microsoft.com> Reviewed-by:
K. Y. Srinivasan <kys@microsoft.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Andy Lutomirski authored
commit 3fb2f423 upstream. It turns out that there's a lurking ABI issue. GCC, when compiling this in a 32-bit program: struct user_desc desc = { .entry_number = idx, .base_addr = base, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0, }; will leave .lm uninitialized. This means that anything in the kernel that reads user_desc.lm for 32-bit tasks is unreliable. Revert the .lm check in set_thread_area(). The value never did anything in the first place. Fixes: 0e58af4e ("x86/tls: Disallow unusual TLS segments") Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/d7875b60e28c512f6a6fc0baf5714d58e7eaadbb.1418856405.git.luto@amacapital.netSigned-off-by:
Ingo Molnar <mingo@kernel.org> [lizf: Backported to 3.4: adjust filename] Signed-off-by:
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Andy Lutomirski authored
commit 0e58af4e upstream. Users have no business installing custom code segments into the GDT, and segments that are not present but are otherwise valid are a historical source of interesting attacks. For completeness, block attempts to set the L bit. (Prior to this patch, the L bit would have been silently dropped.) This is an ABI break. I've checked glibc, musl, and Wine, and none of them look like they'll have any trouble. Note to stable maintainers: this is a hardening patch that fixes no known bugs. Given the possibility of ABI issues, this probably shouldn't be backported quickly. Signed-off-by:
H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: security@kernel.org <security@kernel.org> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by:
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Thomas Gleixner authored
commit c291ee62 upstream. Since the rework of the sparse interrupt code to actually free the unused interrupt descriptors there exists a race between the /proc interfaces to the irq subsystem and the code which frees the interrupt descriptor. CPU0 CPU1 show_interrupts() desc = irq_to_desc(X); free_desc(desc) remove_from_radix_tree(); kfree(desc); raw_spinlock_irq(&desc->lock); /proc/interrupts is the only interface which can actively corrupt kernel memory via the lock access. /proc/stat can only read from freed memory. Extremly hard to trigger, but possible. The interfaces in /proc/irq/N/ are not affected by this because the removal of the proc file is serialized in procfs against concurrent readers/writers. The removal happens before the descriptor is freed. For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue as the descriptor is never freed. It's merely cleared out with the irq descriptor lock held. So any concurrent proc access will either see the old correct value or the cleared out ones. Protect the lookup and access to the irq descriptor in show_interrupts() with the sparse_irq_lock. Provide kstat_irqs_usr() which is protecting the lookup and access with sparse_irq_lock and switch /proc/stat to use it. Document the existing kstat_irqs interfaces so it's clear that the caller needs to take care about protection. The users of these interfaces are either not affected due to SPARSE_IRQ=n or already protected against removal. Fixes: 1f5a5b87 "genirq: Implement a sane sparse_irq allocator" Signed-off-by:
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Andy Lutomirski authored
commit f647d7c1 upstream. Otherwise, if buggy user code points DS or ES into the TLS array, they would be corrupted after a context switch. This also significantly improves the comments and documents some gotchas in the code. Before this patch, the both tests below failed. With this patch, the es test passes, although the gsbase test still fails. ----- begin es test ----- /* * Copyright (c) 2014 Andy Lutomirski * GPL v2 */ static unsigned short GDT3(int idx) { return (idx << 3) | 3; } static int create_tls(int idx, unsigned int base) { struct user_desc desc = { .entry_number = idx, .base_addr = base, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0, }; if (syscall(SYS_set_thread_area, &desc) != 0) err(1, "set_thread_area"); return desc.entry_number; } int main() { int idx = create_tls(-1, 0); printf("Allocated GDT index %d\n", idx); unsigned short orig_es; asm volatile ("mov %%es,%0" : "=rm" (orig_es)); int errors = 0; int total = 1000; for (int i = 0; i < total; i++) { asm volatile ("mov %0,%%es" : : "rm" (GDT3(idx))); usleep(100); unsigned short es; asm volatile ("mov %%es,%0" : "=rm" (es)); asm volatile ("mov %0,%%es" : : "rm" (orig_es)); if (es != GDT3(idx)) { if (errors == 0) printf("[FAIL]\tES changed from 0x%hx to 0x%hx\n", GDT3(idx), es); errors++; } } if (errors) { printf("[FAIL]\tES was corrupted %d/%d times\n", errors, total); return 1; } else { printf("[OK]\tES was preserved\n"); return 0; } } ----- end es test ----- ----- begin gsbase test ----- /* * gsbase.c, a gsbase test * Copyright (c) 2014 Andy Lutomirski * GPL v2 */ static unsigned char *testptr, *testptr2; static unsigned char read_gs_testvals(void) { unsigned char ret; asm volatile ("movb %%gs:%1, %0" : "=r" (ret) : "m" (*testptr)); return ret; } int main() { int errors = 0; testptr = mmap((void *)0x200000000UL, 1, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0); if (testptr == MAP_FAILED) err(1, "mmap"); testptr2 = mmap((void *)0x300000000UL, 1, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0); if (testptr2 == MAP_FAILED) err(1, "mmap"); *testptr = 0; *testptr2 = 1; if (syscall(SYS_arch_prctl, ARCH_SET_GS, (unsigned long)testptr2 - (unsigned long)testptr) != 0) err(1, "ARCH_SET_GS"); usleep(100); if (read_gs_testvals() == 1) { printf("[OK]\tARCH_SET_GS worked\n"); } else { printf("[FAIL]\tARCH_SET_GS failed\n"); errors++; } asm volatile ("mov %0,%%gs" : : "r" (0)); if (read_gs_testvals() == 0) { printf("[OK]\tWriting 0 to gs worked\n"); } else { printf("[FAIL]\tWriting 0 to gs failed\n"); errors++; } usleep(100); if (read_gs_testvals() == 0) { printf("[OK]\tgsbase is still zero\n"); } else { printf("[FAIL]\tgsbase was corrupted\n"); errors++; } return errors == 0 ? 0 : 1; } ----- end gsbase test ----- Signed-off-by:
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Jan Kara authored
commit a682e9c2 upstream. If some error happens in NCP_IOC_SETROOT ioctl, the appropriate error return value is then (in most cases) just overwritten before we return. This can result in reporting success to userspace although error happened. This bug was introduced by commit 2e54eb96 ("BKL: Remove BKL from ncpfs"). Propagate the errors correctly. Coverity id: 1226925. Fixes: 2e54eb96 ("BKL: Remove BKL from ncpfs") Signed-off-by:
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Filipe Manana authored
commit 678886bd upstream. When we abort a transaction we iterate over all the ranges marked as dirty in fs_info->freed_extents[0] and fs_info->freed_extents[1], clear them from those trees, add them back (unpin) to the free space caches and, if the fs was mounted with "-o discard", perform a discard on those regions. Also, after adding the regions to the free space caches, a fitrim ioctl call can see those ranges in a block group's free space cache and perform a discard on the ranges, so the same issue can happen without "-o discard" as well. This causes corruption, affecting one or multiple btree nodes (in the worst case leaving the fs unmountable) because some of those ranges (the ones in the fs_info->pinned_extents tree) correspond to btree nodes/leafs that are referred by the last committed super block - breaking the rule that anything that was committed by a transaction is untouched until the next transaction commits successfully. I ran into this while running in a loop (for several hours) the fstest that I recently submitted: [PATCH] fstests: add btrfs test to stress chunk allocation/removal and fstrim The corruption always happened when a transaction aborted and then fsck complained like this: _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent *** fsck.btrfs output *** Check tree block failed, want=94945280, have=0 Check tree block failed, want=94945280, have=0 Check tree block failed, want=94945280, have=0 Check tree block failed, want=94945280, have=0 Check tree block failed, want=94945280, have=0 read block failed check_tree_block Couldn't open file system In this case 94945280 corresponded to the root of a tree. Using frace what I observed was the following sequence of steps happened: 1) transaction N started, fs_info->pinned_extents pointed to fs_info->freed_extents[0]; 2) node/eb 94945280 is created; 3) eb is persisted to disk; 4) transaction N commit starts, fs_info->pinned_extents now points to fs_info->freed_extents[1], and transaction N completes; 5) transaction N + 1 starts; 6) eb is COWed, and btrfs_free_tree_block() called for this eb; 7) eb range (94945280 to 94945280 + 16Kb) is added to fs_info->pinned_extents (fs_info->freed_extents[1]); 8) Something goes wrong in transaction N + 1, like hitting ENOSPC for example, and the transaction is aborted, turning the fs into readonly mode. The stack trace I got for example: [112065.253935] [<ffffffff8140c7b6>] dump_stack+0x4d/0x66 [112065.254271] [<ffffffff81042984>] warn_slowpath_common+0x7f/0x98 [112065.254567] [<ffffffffa0325990>] ? __btrfs_abort_transaction+0x50/0x10b [btrfs] [112065.261674] [<ffffffff810429e5>] warn_slowpath_fmt+0x48/0x50 [112065.261922] [<ffffffffa032949e>] ? btrfs_free_path+0x26/0x29 [btrfs] [112065.262211] [<ffffffffa0325990>] __btrfs_abort_transaction+0x50/0x10b [btrfs] [112065.262545] [<ffffffffa036b1d6>] btrfs_remove_chunk+0x537/0x58b [btrfs] [112065.262771] [<ffffffffa033840f>] btrfs_delete_unused_bgs+0x1de/0x21b [btrfs] [112065.263105] [<ffffffffa0343106>] cleaner_kthread+0x100/0x12f [btrfs] (...) [112065.264493] ---[ end trace dd7903a975a31a08 ]--- [112065.264673] BTRFS: error (device sdc) in btrfs_remove_chunk:2625: errno=-28 No space left [112065.264997] BTRFS info (device sdc): forced readonly 9) The clear kthread sees that the BTRFS_FS_STATE_ERROR bit is set in fs_info->fs_state and calls btrfs_cleanup_transaction(), which in turn calls btrfs_destroy_pinned_extent(); 10) Then btrfs_destroy_pinned_extent() iterates over all the ranges marked as dirty in fs_info->freed_extents[], and for each one it calls discard, if the fs was mounted with "-o discard", and adds the range to the free space cache of the respective block group; 11) btrfs_trim_block_group(), invoked from the fitrim ioctl code path, sees the free space entries and performs a discard; 12) After an umount and mount (or fsck), our eb's location on disk was full of zeroes, and it should have been untouched, because it was marked as dirty in the fs_info->pinned_extents tree, and therefore used by the trees that the last committed superblock points to. Fix this by not performing a discard and not adding the ranges to the free space caches - it's useless from this point since the fs is now in readonly mode and we won't write free space caches to disk anymore (otherwise we would leak space) nor any new superblock. By not adding the ranges to the free space caches, it prevents other code paths from allocating that space and write to it as well, therefore being safer and simpler. This isn't a new problem, as it's been present since 2011 (git commit acce952b). Signed-off-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
Chris Mason <clm@fb.com> Signed-off-by:
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