From d5cd21eda2d5ed2e5a4eddf8ebc50d9a98eb7791 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 2 Jun 2025 11:33:42 +0200 Subject: [PATCH] 5.10-stable patches added patches: smb-client-fix-use-after-free-in-cifs_fill_dirent.patch smb-client-reset-all-search-buffer-pointers-when-releasing-buffer.patch --- queue-5.10/series | 2 + ...x-use-after-free-in-cifs_fill_dirent.patch | 170 ++++++++++++++++++ ...uffer-pointers-when-releasing-buffer.patch | 42 +++++ 3 files changed, 214 insertions(+) create mode 100644 queue-5.10/smb-client-fix-use-after-free-in-cifs_fill_dirent.patch create mode 100644 queue-5.10/smb-client-reset-all-search-buffer-pointers-when-releasing-buffer.patch diff --git a/queue-5.10/series b/queue-5.10/series index e9e8732f7d..58db67b064 100644 --- a/queue-5.10/series +++ b/queue-5.10/series @@ -251,3 +251,5 @@ spi-spi-fsl-dspi-halt-the-module-after-a-new-message.patch spi-spi-fsl-dspi-reset-sr-flags-before-sending-a-new.patch kbuild-disable-wdefault-const-init-unsafe.patch drm-i915-gvt-fix-unterminated-string-initialization-warning.patch +smb-client-fix-use-after-free-in-cifs_fill_dirent.patch +smb-client-reset-all-search-buffer-pointers-when-releasing-buffer.patch diff --git a/queue-5.10/smb-client-fix-use-after-free-in-cifs_fill_dirent.patch b/queue-5.10/smb-client-fix-use-after-free-in-cifs_fill_dirent.patch new file mode 100644 index 0000000000..c62ed3480c --- /dev/null +++ b/queue-5.10/smb-client-fix-use-after-free-in-cifs_fill_dirent.patch @@ -0,0 +1,170 @@ +From a7a8fe56e932a36f43e031b398aef92341bf5ea0 Mon Sep 17 00:00:00 2001 +From: Wang Zhaolong +Date: Fri, 16 May 2025 17:12:55 +0800 +Subject: smb: client: Fix use-after-free in cifs_fill_dirent + +From: Wang Zhaolong + +commit a7a8fe56e932a36f43e031b398aef92341bf5ea0 upstream. + +There is a race condition in the readdir concurrency process, which may +access the rsp buffer after it has been released, triggering the +following KASAN warning. + + ================================================================== + BUG: KASAN: slab-use-after-free in cifs_fill_dirent+0xb03/0xb60 [cifs] + Read of size 4 at addr ffff8880099b819c by task a.out/342975 + + CPU: 2 UID: 0 PID: 342975 Comm: a.out Not tainted 6.15.0-rc6+ #240 PREEMPT(full) + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 + Call Trace: + + dump_stack_lvl+0x53/0x70 + print_report+0xce/0x640 + kasan_report+0xb8/0xf0 + cifs_fill_dirent+0xb03/0xb60 [cifs] + cifs_readdir+0x12cb/0x3190 [cifs] + iterate_dir+0x1a1/0x520 + __x64_sys_getdents+0x134/0x220 + do_syscall_64+0x4b/0x110 + entry_SYSCALL_64_after_hwframe+0x76/0x7e + RIP: 0033:0x7f996f64b9f9 + Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 + f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 + f0 ff ff 0d f7 c3 0c 00 f7 d8 64 89 8 + RSP: 002b:00007f996f53de78 EFLAGS: 00000207 ORIG_RAX: 000000000000004e + RAX: ffffffffffffffda RBX: 00007f996f53ecdc RCX: 00007f996f64b9f9 + RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 + RBP: 00007f996f53dea0 R08: 0000000000000000 R09: 0000000000000000 + R10: 0000000000000000 R11: 0000000000000207 R12: ffffffffffffff88 + R13: 0000000000000000 R14: 00007ffc8cd9a500 R15: 00007f996f51e000 + + + Allocated by task 408: + kasan_save_stack+0x20/0x40 + kasan_save_track+0x14/0x30 + __kasan_slab_alloc+0x6e/0x70 + kmem_cache_alloc_noprof+0x117/0x3d0 + mempool_alloc_noprof+0xf2/0x2c0 + cifs_buf_get+0x36/0x80 [cifs] + allocate_buffers+0x1d2/0x330 [cifs] + cifs_demultiplex_thread+0x22b/0x2690 [cifs] + kthread+0x394/0x720 + ret_from_fork+0x34/0x70 + ret_from_fork_asm+0x1a/0x30 + + Freed by task 342979: + kasan_save_stack+0x20/0x40 + kasan_save_track+0x14/0x30 + kasan_save_free_info+0x3b/0x60 + __kasan_slab_free+0x37/0x50 + kmem_cache_free+0x2b8/0x500 + cifs_buf_release+0x3c/0x70 [cifs] + cifs_readdir+0x1c97/0x3190 [cifs] + iterate_dir+0x1a1/0x520 + __x64_sys_getdents64+0x134/0x220 + do_syscall_64+0x4b/0x110 + entry_SYSCALL_64_after_hwframe+0x76/0x7e + + The buggy address belongs to the object at ffff8880099b8000 + which belongs to the cache cifs_request of size 16588 + The buggy address is located 412 bytes inside of + freed 16588-byte region [ffff8880099b8000, ffff8880099bc0cc) + + The buggy address belongs to the physical page: + page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99b8 + head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 + anon flags: 0x80000000000040(head|node=0|zone=1) + page_type: f5(slab) + raw: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001 + raw: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000 + head: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001 + head: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000 + head: 0080000000000003 ffffea0000266e01 00000000ffffffff 00000000ffffffff + head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 + page dumped because: kasan: bad access detected + + Memory state around the buggy address: + ffff8880099b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb + ffff8880099b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb + >ffff8880099b8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb + ^ + ffff8880099b8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb + ffff8880099b8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb + ================================================================== + +POC is available in the link [1]. + +The problem triggering process is as follows: + +Process 1 Process 2 +----------------------------------------------------------------- +cifs_readdir + /* file->private_data == NULL */ + initiate_cifs_search + cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL); + smb2_query_dir_first ->query_dir_first() + SMB2_query_directory + SMB2_query_directory_init + cifs_send_recv + smb2_parse_query_directory + srch_inf->ntwrk_buf_start = (char *)rsp; + srch_inf->srch_entries_start = (char *)rsp + ... + srch_inf->last_entry = (char *)rsp + ... + srch_inf->smallBuf = true; + find_cifs_entry + /* if (cfile->srch_inf.ntwrk_buf_start) */ + cifs_small_buf_release(cfile->srch_inf // free + + cifs_readdir ->iterate_shared() + /* file->private_data != NULL */ + find_cifs_entry + /* in while (...) loop */ + smb2_query_dir_next ->query_dir_next() + SMB2_query_directory + SMB2_query_directory_init + cifs_send_recv + compound_send_recv + smb_send_rqst + __smb_send_rqst + rc = -ERESTARTSYS; + /* if (fatal_signal_pending()) */ + goto out; + return rc + /* if (cfile->srch_inf.last_entry) */ + cifs_save_resume_key() + cifs_fill_dirent // UAF + /* if (rc) */ + return -ENOENT; + +Fix this by ensuring the return code is checked before using pointers +from the srch_inf. + +Link: https://bugzilla.kernel.org/show_bug.cgi?id=220131 [1] +Fixes: a364bc0b37f1 ("[CIFS] fix saving of resume key before CIFSFindNext") +Cc: stable@vger.kernel.org +Reviewed-by: Paulo Alcantara (Red Hat) +Signed-off-by: Wang Zhaolong +Signed-off-by: Steve French +Signed-off-by: Wang Zhaolong +Signed-off-by: Greg Kroah-Hartman +--- + fs/cifs/readdir.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +--- a/fs/cifs/readdir.c ++++ b/fs/cifs/readdir.c +@@ -778,11 +778,11 @@ find_cifs_entry(const unsigned int xid, + rc = server->ops->query_dir_next(xid, tcon, &cfile->fid, + search_flags, + &cfile->srch_inf); ++ if (rc) ++ return -ENOENT; + /* FindFirst/Next set last_entry to NULL on malformed reply */ + if (cfile->srch_inf.last_entry) + cifs_save_resume_key(cfile->srch_inf.last_entry, cfile); +- if (rc) +- return -ENOENT; + } + if (index_to_find < cfile->srch_inf.index_of_last_entry) { + /* we found the buffer that contains the entry */ diff --git a/queue-5.10/smb-client-reset-all-search-buffer-pointers-when-releasing-buffer.patch b/queue-5.10/smb-client-reset-all-search-buffer-pointers-when-releasing-buffer.patch new file mode 100644 index 0000000000..83654c35e5 --- /dev/null +++ b/queue-5.10/smb-client-reset-all-search-buffer-pointers-when-releasing-buffer.patch @@ -0,0 +1,42 @@ +From e48f9d849bfdec276eebf782a84fd4dfbe1c14c0 Mon Sep 17 00:00:00 2001 +From: Wang Zhaolong +Date: Fri, 16 May 2025 17:12:56 +0800 +Subject: smb: client: Reset all search buffer pointers when releasing buffer + +From: Wang Zhaolong + +commit e48f9d849bfdec276eebf782a84fd4dfbe1c14c0 upstream. + +Multiple pointers in struct cifs_search_info (ntwrk_buf_start, +srch_entries_start, and last_entry) point to the same allocated buffer. +However, when freeing this buffer, only ntwrk_buf_start was set to NULL, +while the other pointers remained pointing to freed memory. + +This is defensive programming to prevent potential issues with stale +pointers. While the active UAF vulnerability is fixed by the previous +patch, this change ensures consistent pointer state and more robust error +handling. + +Signed-off-by: Wang Zhaolong +Cc: stable@vger.kernel.org +Reviewed-by: Paulo Alcantara (Red Hat) +Signed-off-by: Steve French +Signed-off-by: Wang Zhaolong +Signed-off-by: Greg Kroah-Hartman +--- + fs/cifs/readdir.c | 3 +++ + 1 file changed, 3 insertions(+) + +--- a/fs/cifs/readdir.c ++++ b/fs/cifs/readdir.c +@@ -755,7 +755,10 @@ find_cifs_entry(const unsigned int xid, + else + cifs_buf_release(cfile->srch_inf. + ntwrk_buf_start); ++ /* Reset all pointers to the network buffer to prevent stale references */ + cfile->srch_inf.ntwrk_buf_start = NULL; ++ cfile->srch_inf.srch_entries_start = NULL; ++ cfile->srch_inf.last_entry = NULL; + } + rc = initiate_cifs_search(xid, file, full_path); + if (rc) { -- 2.47.2