user/sven/linux.git/fs/proc, branch v6.1.72

watchdog: move softlockup_panic back to early_param

2023-11-28T17:07:09Z

commit 8b793bcda61f6c3ed4f5b2ded7530ef6749580cb upstream. Setting softlockup_panic from do_sysctl_args() causes it to take effect later in boot. The lockup detector is enabled before SMP is brought online, but do_sysctl_args runs afterwards. If a user wants to set softlockup_panic on boot and have it trigger should a softlockup occur during onlining of the non-boot processors, they could do this prior to commit f117955a2255 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases"). However, after this commit the value of softlockup_panic is set too late to be of help for this type of problem. Restore the prior behavior. Signed-off-by: Krister Johansen Cc: stable@vger.kernel.org Fixes: f117955a2255 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases") Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

proc: sysctl: prevent aliased sysctls from getting passed to init

2023-11-28T17:07:08Z

commit 8001f49394e353f035306a45bcf504f06fca6355 upstream. The code that checks for unknown boot options is unaware of the sysctl alias facility, which maps bootparams to sysctl values. If a user sets an old value that has a valid alias, a message about an invalid parameter will be printed during boot, and the parameter will get passed to init. Fix by checking for the existence of aliased parameters in the unknown boot parameter code. If an alias exists, don't return an error or pass the value to init. Signed-off-by: Krister Johansen Cc: stable@vger.kernel.org Fixes: 0a477e1ae21b ("kernel/sysctl: support handling command line aliases") Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

proc: nommu: fix empty /proc//maps

2023-10-06T12:56:42Z

[ Upstream commit fe4419801617514765974f3e796269bc512ad146 ] On no-MMU, /proc//maps reads as an empty file. This happens because find_vma(mm, 0) always returns NULL (assuming no vma actually contains the zero address, which is normally the case). To fix this bug and improve the maintainability in the future, this patch makes the no-MMU implementation as similar as possible to the MMU implementation. The only remaining differences are the lack of hold/release_task_mempolicy and the extra code to shoehorn the gate vma into the iterator. This has been tested on top of 6.5.3 on an STM32F746. Link: https://lkml.kernel.org/r/20230915160055.971059-2-ben.wolsieffer@hefring.com Fixes: 0c563f148043 ("proc: remove VMA rbtree use from nommu") Signed-off-by: Ben Wolsieffer Cc: Davidlohr Bueso Cc: Giulio Benetti Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: Oleg Nesterov Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

proc: nommu: /proc//maps: release mmap read lock

2023-10-06T12:56:42Z

[ Upstream commit 578d7699e5c2add8c2e9549d9d75dfb56c460cb3 ] The no-MMU implementation of /proc//map doesn't normally release the mmap read lock, because it uses !IS_ERR_OR_NULL(_vml) to determine whether to release the lock. Since _vml is NULL when the end of the mappings is reached, the lock is not released. Reading /proc/1/maps twice doesn't cause a hang because it only takes the read lock, which can be taken multiple times and therefore doesn't show any problem if the lock isn't released. Instead, you need to perform some operation that attempts to take the write lock after reading /proc//maps. To actually reproduce the bug, compile the following code as 'proc_maps_bug': #include #include #include int main(int argc, char *argv[]) { void *buf; sleep(1); buf = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); puts("mmap returned"); return 0; } Then, run: ./proc_maps_bug &; cat /proc/$!/maps; fg Without this patch, mmap() will hang and the command will never complete. This code was incorrectly adapted from the MMU implementation, which at the time released the lock in m_next() before returning the last entry. The MMU implementation has diverged further from the no-MMU version since then, so this patch brings their locking and error handling into sync, fixing the bug and hopefully avoiding similar issues in the future. Link: https://lkml.kernel.org/r/20230914163019.4050530-2-ben.wolsieffer@hefring.com Fixes: 47fecca15c09 ("fs/proc/task_nommu.c: don't use priv->task->mm") Signed-off-by: Ben Wolsieffer Acked-by: Oleg Nesterov Cc: Giulio Benetti Cc: Greg Ungerer Cc: Signed-off-by: Andrew Morton Stable-dep-of: fe4419801617 ("proc: nommu: fix empty /proc//maps") Signed-off-by: Sasha Levin

procfs: block chmod on /proc/thread-self/comm

2023-09-13T07:43:02Z

commit ccf61486fe1e1a48e18c638d1813cda77b3c0737 upstream. Due to an oversight in commit 1b3044e39a89 ("procfs: fix pthread cross-thread naming if !PR_DUMPABLE") in switching from REG to NOD, chmod operations on /proc/thread-self/comm were no longer blocked as they are on almost all other procfs files. A very similar situation with /proc/self/environ was used to as a root exploit a long time ago, but procfs has SB_I_NOEXEC so this is simply a correctness issue. Ref: https://lwn.net/Articles/191954/ Ref: 6d76fa58b050 ("Don't allow chmod() on the /proc// files") Fixes: 1b3044e39a89 ("procfs: fix pthread cross-thread naming if !PR_DUMPABLE") Cc: stable@vger.kernel.org # v4.7+ Signed-off-by: Aleksa Sarai Message-Id: <20230713141001.27046-1-cyphar@cyphar.com> Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

proc/vmcore: fix signedness bug in read_from_oldmem()

2023-08-03T08:24:14Z

commit 641db40f3afe7998011bfabc726dba3e698f8196 upstream. The bug is the error handling: if (tmp < nr_bytes) { "tmp" can hold negative error codes but because "nr_bytes" is type size_t the negative error codes are treated as very high positive values (success). Fix this by changing "nr_bytes" to type ssize_t. The "nr_bytes" variable is used to store values between 1 and PAGE_SIZE and they can fit in ssize_t without any issue. Link: https://lkml.kernel.org/r/b55f7eed-1c65-4adc-95d1-6c7c65a54a6e@moroto.mountain Fixes: 5d8de293c224 ("vmcore: convert copy_oldmem_page() to take an iov_iter") Signed-off-by: Dan Carpenter Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Baoquan He Cc: Dave Young Cc: Vivek Goyal Cc: Alexey Dobriyan Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

sysctl: clarify register_sysctl_init() base directory order

2023-05-17T09:53:46Z

commit 228b09de936395ddd740df3522ea35ae934830d8 upstream. Relatively new docs which I added which hinted the base directories needed to be created before is wrong, remove that incorrect comment. This has been hinted before by Eric twice already [0] [1], I had just not verified that until now. Now that I've verified that updates the docs to relax the context described. [0] https://lkml.kernel.org/r/875ys0azt8.fsf@email.froward.int.ebiederm.org [1] https://lkml.kernel.org/r/87ftbiud6s.fsf@x220.int.ebiederm.org Cc: stable@vger.kernel.org # v5.17 Cc: Christian Brauner Cc: Kefeng Wang Suggested-by: Eric W. Biederman Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

proc_sysctl: enhance documentation

2023-05-17T09:53:45Z

commit 1dc8689e4cc651e21566e10206a84c4006e81fb1 upstream. Expand documentation to clarify: o that paths don't need to exist for the new API callers o clarify that we *require* callers to keep the memory of the table around during the lifetime of the sysctls o annotate routines we are trying to deprecate and later remove Cc: stable@vger.kernel.org # v5.17 Cc: Christian Brauner Cc: Kefeng Wang Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

proc_sysctl: update docs for __register_sysctl_table()

2023-05-17T09:53:45Z

commit 67ff32289acad9ed338cd9f2351b44939e55163e upstream. Update the docs for __register_sysctl_table() to make it clear no child entries can be passed. When the child is true these are non-leaf entries on the ctl table and sysctl treats these as directories. The point to __register_sysctl_table() is to deal only with directories not part of the ctl table where thay may riside, to be simple and avoid recursion. While at it, hint towards using long on extra1 and extra2 later. Cc: stable@vger.kernel.org # v5.17 Cc: Christian Brauner Cc: Kefeng Wang Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps

2023-02-09T10:28:20Z

commit 3489dbb696d25602aea8c3e669a6d43b76bd5358 upstream. Patch series "Fixes for hugetlb mapcount at most 1 for shared PMDs". This issue of mapcount in hugetlb pages referenced by shared PMDs was discussed in [1]. The following two patches address user visible behavior caused by this issue. [1] https://lore.kernel.org/linux-mm/Y9BF+OCdWnCSilEu@monkey/ This patch (of 2): A hugetlb page will have a mapcount of 1 if mapped by multiple processes via a shared PMD. This is because only the first process increases the map count, and subsequent processes just add the shared PMD page to their page table. page_mapcount is being used to decide if a hugetlb page is shared or private in /proc/PID/smaps. Pages referenced via a shared PMD were incorrectly being counted as private. To fix, check for a shared PMD if mapcount is 1. If a shared PMD is found count the hugetlb page as shared. A new helper to check for a shared PMD is added. [akpm@linux-foundation.org: simplification, per David] [akpm@linux-foundation.org: hugetlb.h: include page_ref.h for page_count()] Link: https://lkml.kernel.org/r/20230126222721.222195-2-mike.kravetz@oracle.com Fixes: 25ee01a2fca0 ("mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smaps") Signed-off-by: Mike Kravetz Acked-by: Peter Xu Cc: David Hildenbrand Cc: James Houghton Cc: Matthew Wilcox Cc: Michal Hocko Cc: Muchun Song Cc: Naoya Horiguchi Cc: Vishal Moola (Oracle) Cc: Yang Shi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman