5.10-stable patches

added patches:
	mm-shmem-fix-data-race-in-shmem_getattr.patch

diff --git a/queue-5.10/mm-shmem-fix-data-race-in-shmem_getattr.patch b/queue-5.10/mm-shmem-fix-data-race-in-shmem_getattr.patch
new file mode 100644 (file)
index 0000000..58ebe40
--- /dev/null
+++ b/queue-5.10/mm-shmem-fix-data-race-in-shmem_getattr.patch
@@ -0,0 +1,96 @@
+From d949d1d14fa281ace388b1de978e8f2cd52875cf Mon Sep 17 00:00:00 2001
+From: Jeongjun Park <aha310510@gmail.com>
+Date: Mon, 9 Sep 2024 21:35:58 +0900
+Subject: mm: shmem: fix data-race in shmem_getattr()
+
+From: Jeongjun Park <aha310510@gmail.com>
+
+commit d949d1d14fa281ace388b1de978e8f2cd52875cf upstream.
+
+I got the following KCSAN report during syzbot testing:
+
+==================================================================
+BUG: KCSAN: data-race in generic_fillattr / inode_set_ctime_current
+
+write to 0xffff888102eb3260 of 4 bytes by task 6565 on cpu 1:
+ inode_set_ctime_to_ts include/linux/fs.h:1638 [inline]
+ inode_set_ctime_current+0x169/0x1d0 fs/inode.c:2626
+ shmem_mknod+0x117/0x180 mm/shmem.c:3443
+ shmem_create+0x34/0x40 mm/shmem.c:3497
+ lookup_open fs/namei.c:3578 [inline]
+ open_last_lookups fs/namei.c:3647 [inline]
+ path_openat+0xdbc/0x1f00 fs/namei.c:3883
+ do_filp_open+0xf7/0x200 fs/namei.c:3913
+ do_sys_openat2+0xab/0x120 fs/open.c:1416
+ do_sys_open fs/open.c:1431 [inline]
+ __do_sys_openat fs/open.c:1447 [inline]
+ __se_sys_openat fs/open.c:1442 [inline]
+ __x64_sys_openat+0xf3/0x120 fs/open.c:1442
+ x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258
+ do_syscall_x64 arch/x86/entry/common.c:52 [inline]
+ do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83
+ entry_SYSCALL_64_after_hwframe+0x76/0x7e
+
+read to 0xffff888102eb3260 of 4 bytes by task 3498 on cpu 0:
+ inode_get_ctime_nsec include/linux/fs.h:1623 [inline]
+ inode_get_ctime include/linux/fs.h:1629 [inline]
+ generic_fillattr+0x1dd/0x2f0 fs/stat.c:62
+ shmem_getattr+0x17b/0x200 mm/shmem.c:1157
+ vfs_getattr_nosec fs/stat.c:166 [inline]
+ vfs_getattr+0x19b/0x1e0 fs/stat.c:207
+ vfs_statx_path fs/stat.c:251 [inline]
+ vfs_statx+0x134/0x2f0 fs/stat.c:315
+ vfs_fstatat+0xec/0x110 fs/stat.c:341
+ __do_sys_newfstatat fs/stat.c:505 [inline]
+ __se_sys_newfstatat+0x58/0x260 fs/stat.c:499
+ __x64_sys_newfstatat+0x55/0x70 fs/stat.c:499
+ x64_sys_call+0x141f/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:263
+ do_syscall_x64 arch/x86/entry/common.c:52 [inline]
+ do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83
+ entry_SYSCALL_64_after_hwframe+0x76/0x7e
+
+value changed: 0x2755ae53 -> 0x27ee44d3
+
+Reported by Kernel Concurrency Sanitizer on:
+CPU: 0 UID: 0 PID: 3498 Comm: udevd Not tainted 6.11.0-rc6-syzkaller-00326-gd1f2d51b711a-dirty #0
+Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
+==================================================================
+
+When calling generic_fillattr(), if you don't hold read lock, data-race
+will occur in inode member variables, which can cause unexpected
+behavior.
+
+Since there is no special protection when shmem_getattr() calls
+generic_fillattr(), data-race occurs by functions such as shmem_unlink()
+or shmem_mknod(). This can cause unexpected results, so commenting it out
+is not enough.
+
+Therefore, when calling generic_fillattr() from shmem_getattr(), it is
+appropriate to protect the inode using inode_lock_shared() and
+inode_unlock_shared() to prevent data-race.
+
+Link: https://lkml.kernel.org/r/20240909123558.70229-1-aha310510@gmail.com
+Fixes: 44a30220bc0a ("shmem: recalculate file inode when fstat")
+Signed-off-by: Jeongjun Park <aha310510@gmail.com>
+Reported-by: syzbot <syzkaller@googlegroup.com>
+Cc: Hugh Dickins <hughd@google.com>
+Cc: Yu Zhao <yuzhao@google.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/shmem.c |    2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/mm/shmem.c
++++ b/mm/shmem.c
+@@ -1077,7 +1077,9 @@ static int shmem_getattr(const struct pa
+               shmem_recalc_inode(inode);
+               spin_unlock_irq(&info->lock);
+       }
++      inode_lock_shared(inode);
+       generic_fillattr(inode, stat);
++      inode_unlock_shared(inode);
+ 
+       if (is_huge_enabled(sb_info))
+               stat->blksize = HPAGE_PMD_SIZE;

diff --git a/queue-5.10/series b/queue-5.10/series
index 0c0c8ce2a0b420f6f60ae11d2b792d50ed10fc8f..83e7799298b34c778d5671df252b20c861eccef2 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -103,3 +103,4 @@ riscv-remove-duplicated-get_rm.patch
 ocfs2-pass-u64-to-ocfs2_truncate_inline-maybe-overfl.patch
 x86-bugs-use-code-segment-selector-for-verw-operand.patch
 nilfs2-fix-kernel-bug-due-to-missing-clearing-of-checked-flag.patch
+mm-shmem-fix-data-race-in-shmem_getattr.patch