BMC/Intel-BMC/linux.git/fs/proc, branch v4.18.18

proc: restrict kernel stack dumps to root

2018-10-10T06:56:08+00:00

commit f8a00cef17206ecd1b30d3d9f99e10d9fa707aa7 upstream. Currently, you can use /proc/self/task/*/stack to cause a stack walk on a task you control while it is running on another CPU. That means that the stack can change under the stack walker. The stack walker does have guards against going completely off the rails and into random kernel memory, but it can interpret random data from your kernel stack as instruction pointers and stack pointers. This can cause exposure of kernel stack contents to userspace. Restrict the ability to inspect kernel stacks of arbitrary tasks to root in order to prevent a local attacker from exploiting racy stack unwinding to leak kernel task stack contents. See the added comment for a longer rationale. There don't seem to be any users of this userspace API that can't gracefully bail out if reading from the file fails. Therefore, I believe that this change is unlikely to break things. In the case that this patch does end up needing a revert, the next-best solution might be to fake a single-entry stack based on wchan. Link: http://lkml.kernel.org/r/20180927153316.200286-1-jannh@google.com Fixes: 2ec220e27f50 ("proc: add /proc/*/stack") Signed-off-by: Jann Horn Acked-by: Kees Cook Cc: Alexey Dobriyan Cc: Ken Chen Cc: Will Deacon Cc: Laura Abbott Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Josh Poimboeuf Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H . Peter Anvin" Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

fs/proc/kcore.c: use __pa_symbol() for KCORE_TEXT list entries

2018-09-15T07:46:46+00:00

[ Upstream commit df865e8337c397471b95f51017fea559bc8abb4a ] elf_kcore_store_hdr() uses __pa() to find the physical address of KCORE_RAM or KCORE_TEXT entries exported as program headers. This trips CONFIG_DEBUG_VIRTUAL's checks, as the KCORE_TEXT entries are not in the linear map. Handle these two cases separately, using __pa_symbol() for the KCORE_TEXT entries. Link: http://lkml.kernel.org/r/20180711131944.15252-1-james.morse@arm.com Signed-off-by: James Morse Cc: Alexey Dobriyan Cc: Omar Sandoval Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fs/proc/vmcore.c: hide vmcoredd_mmap_dumps() for nommu builds

2018-09-15T07:46:45+00:00

[ Upstream commit a2036a1ef2ee91acab01a0ae4a534070691a42ec ] Without CONFIG_MMU, we get a build warning: fs/proc/vmcore.c:228:12: error: 'vmcoredd_mmap_dumps' defined but not used [-Werror=unused-function] static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, The function is only referenced from an #ifdef'ed caller, so this uses the same #ifdef around it. Link: http://lkml.kernel.org/r/20180525213526.2117790-1-arnd@arndb.de Fixes: 7efe48df8a3d ("vmcore: append device dumps to vmcore as elf notes") Signed-off-by: Arnd Bergmann Cc: Ganesh Goudar Cc: "David S. Miller" Cc: Rahul Lakkireddy Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps*

2018-07-14T18:11:09+00:00

Thomas reports: "While looking around in /proc on my v4.14.52 system I noticed that all processes got a lot of "Locked" memory in /proc/*/smaps. A lot more memory than a regular user can usually lock with mlock(). Commit 493b0e9d945f (in v4.14-rc1) seems to have changed the behavior of "Locked". Before that commit the code was like this. Notice the VM_LOCKED check. (vma->vm_flags & VM_LOCKED) ? (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); After that commit Locked is now the same as Pss: (unsigned long)(mss->pss >> (10 + PSS_SHIFT))); This looks like a mistake." Indeed, the commit has added mss->pss_locked with the correct value that depends on VM_LOCKED, but forgot to actually use it. Fix it. Link: http://lkml.kernel.org/r/ebf6c7fb-fec3-6a26-544f-710ed193c154@suse.cz Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Vlastimil Babka Reported-by: Thomas Lindroth Cc: Alexey Dobriyan Cc: Daniel Colascione Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-07-01T19:32:19+00:00

Pull vfs fix from Al Viro: "Followup to procfs-seq_file series this window" This fixes a memory leak by making sure that proc seq files release any private data on close. The 'proc_seq_open' has to be properly paired with 'proc_seq_release' that releases the extra private data. * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: proc: add proc_seq_release

proc: add proc_seq_release

2018-06-28T00:44:38+00:00

kmemleak reported some memory leak on reading proc files. After adding some debug lines, find that proc_seq_fops is using seq_release as release handler, which won't handle the free of 'private' field of seq_file, while in fact the open handler proc_seq_open could create the private data with __seq_open_private when state_size is greater than zero. So after reading files created with proc_create_seq_private, such as /proc/timer_list and /proc/vmallocinfo, the private mem of a seq_file is not freed. Fix it by adding the paired proc_seq_release as the default release handler of proc_seq_ops instead of seq_release. Fixes: 44414d82cfe0 ("proc: introduce proc_create_seq_private") Reviewed-by: Christoph Hellwig CC: Christoph Hellwig Signed-off-by: Chunyu Hu Signed-off-by: Al Viro

proc: fix missing final NUL in get_mm_cmdline() rewrite

2018-06-20T06:38:28+00:00

The rewrite of the cmdline fetching missed the fact that we used to also return the final terminating NUL character of the last argument. I hadn't noticed, and none of the tools I tested cared, but something obviously must care, because Michal Kubecek noticed the change in behavior. Tweak the "find the end" logic to actually include the NUL character, and once past the eend of argv, always start the strnlen() at the expected (original) argument end. This whole "allow people to rewrite their arguments in place" is a nasty hack and requires that odd slop handling at the end of the argv array, but it's our traditional model, so we continue to support it. Repored-and-bisected-by: Michal Kubecek Reviewed-and-tested-by: Michal Kubecek Cc: Alexey Dobriyan Signed-off-by: Linus Torvalds

Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-06-16T07:32:04+00:00

Pull AFS updates from Al Viro: "Assorted AFS stuff - ended up in vfs.git since most of that consists of David's AFS-related followups to Christoph's procfs series" * 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: afs: Optimise callback breaking by not repeating volume lookup afs: Display manually added cells in dynamic root mount afs: Enable IPv6 DNS lookups afs: Show all of a server's addresses in /proc/fs/afs/servers afs: Handle CONFIG_PROC_FS=n proc: Make inline name size calculation automatic afs: Implement network namespacing afs: Mark afs_net::ws_cell as __rcu and set using rcu functions afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus() proc: Add a way to make network proc files writable afs: Rearrange fs/afs/proc.c to remove remaining predeclarations. afs: Rearrange fs/afs/proc.c to move the show routines up afs: Rearrange fs/afs/proc.c by moving fops and open functions down afs: Move /proc management functions to the end of the file

proc: Make inline name size calculation automatic

2018-06-15T04:48:57+00:00

Make calculation of the size of the inline name in struct proc_dir_entry automatic, rather than having to manually encode the numbers and failing to allow for lockdep. Require a minimum inline name size of 33+1 to allow for names that look like two hex numbers with a dash between. Reported-by: Al Viro Signed-off-by: David Howells Signed-off-by: Al Viro

Merge branch 'akpm' (patches from Andrew)

2018-06-14T23:51:42+00:00

Merge more updates from Andrew Morton: - MM remainders - various misc things - kcov updates * emailed patches from Andrew Morton : (27 commits) lib/test_printf.c: call wait_for_random_bytes() before plain %p tests hexagon: drop the unused variable zero_page_mask hexagon: fix printk format warning in setup.c mm: fix oom_kill event handling treewide: use PHYS_ADDR_MAX to avoid type casting ULLONG_MAX mm: use octal not symbolic permissions ipc: use new return type vm_fault_t sysvipc/sem: mitigate semnum index against spectre v1 fault-injection: reorder config entries arm: port KCOV to arm sched/core / kcov: avoid kcov_area during task switch kcov: prefault the kcov_area kcov: ensure irq code sees a valid area kernel/relay.c: change return type to vm_fault_t exofs: avoid VLA in structures coredump: fix spam with zero VMA process fat: use fat_fs_error() instead of BUG_ON() in __fat_get_block() proc: skip branch in /proc/*/* lookup mremap: remove LATENCY_LIMIT from mremap to reduce the number of TLB shootdowns mm/memblock: add missing include ...