From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E0E627867D; Mon, 8 Apr 2024 13:48:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712584101; cv=none; b=Xa8E0Toqq9RSL9hGANIyNrDcBT0A/gtRw/5UzdoAQDd02pPHgB+FzoF7Y3v4btUBCRcv1xpYgRLhzwURdJxm7SYdWVIgPlZLB4qdxttmeI8DOUDu7FNPhcePen8YcImUb9UtFb3cnvPMcSglKKwQOXBEVcZvertZLh4f06ECVEM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712584101; c=relaxed/simple; bh=EGpmzlJvt611k9tG5RiVZ+OJ6RHmDzTY5GwaB8Nj6Xg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EEtxlENyoO43EHJjzkgcI+dYbxN9c2jYGcGUV1+hhpmf5ITfMpSfsBhEqBUEuRw6bt0IyfmkWTXveggJEDWOct1zNr7R0ze+OAwPGQ9mGT/63tA1BiDLiha4B/f3QBYN4eaEbLpvnH3e0U0Q/y2VJGB+9Ue6CUX90kxnOMGti3I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sgwETn4h; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sgwETn4h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F5A7C433F1; Mon, 8 Apr 2024 13:48:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712584100; bh=EGpmzlJvt611k9tG5RiVZ+OJ6RHmDzTY5GwaB8Nj6Xg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sgwETn4hS8HHyFc/tpfxDFU2rvtialxozHZhavl7nvMZZcgCVsK1/+sl4jZ3oy992 4UVJqkfkb2KNENM7MjO4gtMqQv2wMrBbht6y6xrfNivL3STjKOW1hq7YiJFVmilulh 4gyxghQMgSu7A47eUF1G1xQWgIeT/DuYvMM9zGp4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Amir Goldstein , Jan Kara , Chuck Lever Subject: [PATCH 5.15 334/690] fanotify: refine the validation checks on non-dir inode mask Date: Mon, 8 Apr 2024 14:53:20 +0200 Message-ID: <20240408125411.704847176@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125359.506372836@linuxfoundation.org> References: <20240408125359.506372836@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein [ Upstream commit 8698e3bab4dd7968666e84e111d0bfd17c040e77 ] Commit ceaf69f8eadc ("fanotify: do not allow setting dirent events in mask of non-dir") added restrictions about setting dirent events in the mask of a non-dir inode mark, which does not make any sense. For backward compatibility, these restictions were added only to new (v5.17+) APIs. It also does not make any sense to set the flags FAN_EVENT_ON_CHILD or FAN_ONDIR in the mask of a non-dir inode. Add these flags to the dir-only restriction of the new APIs as well. Move the check of the dir-only flags for new APIs into the helper fanotify_events_supported(), which is only called for FAN_MARK_ADD, because there is no need to error on an attempt to remove the dir-only flags from non-dir inode. Fixes: ceaf69f8eadc ("fanotify: do not allow setting dirent events in mask of non-dir") Link: https://lore.kernel.org/linux-fsdevel/20220627113224.kr2725conevh53u4@quack3.lan/ Link: https://lore.kernel.org/r/20220627174719.2838175-1-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara [ cel: adjusted to apply on v5.15.y ] Signed-off-by: Chuck Lever --- fs/notify/fanotify/fanotify_user.c | 30 +++++++++++++++--------------- include/linux/fanotify.h | 4 ++++ 2 files changed, 19 insertions(+), 15 deletions(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 6db5a0b03a78d..433c89fdcf0cd 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1509,10 +1509,14 @@ static int fanotify_test_fid(struct dentry *dentry) return 0; } -static int fanotify_events_supported(struct path *path, __u64 mask, +static int fanotify_events_supported(struct fsnotify_group *group, + struct path *path, __u64 mask, unsigned int flags) { unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS; + /* Strict validation of events in non-dir inode mask with v5.17+ APIs */ + bool strict_dir_events = FAN_GROUP_FLAG(group, FAN_REPORT_TARGET_FID) || + (mask & FAN_RENAME); /* * Some filesystems such as 'proc' acquire unusual locks when opening @@ -1540,6 +1544,15 @@ static int fanotify_events_supported(struct path *path, __u64 mask, path->mnt->mnt_sb->s_flags & SB_NOUSER) return -EINVAL; + /* + * We shouldn't have allowed setting dirent events and the directory + * flags FAN_ONDIR and FAN_EVENT_ON_CHILD in mask of non-dir inode, + * but because we always allowed it, error only when using new APIs. + */ + if (strict_dir_events && mark_type == FAN_MARK_INODE && + !d_is_dir(path->dentry) && (mask & FANOTIFY_DIRONLY_EVENT_BITS)) + return -ENOTDIR; + return 0; } @@ -1686,7 +1699,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, goto fput_and_out; if (flags & FAN_MARK_ADD) { - ret = fanotify_events_supported(&path, mask, flags); + ret = fanotify_events_supported(group, &path, mask, flags); if (ret) goto path_put_and_out; } @@ -1709,19 +1722,6 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, else mnt = path.mnt; - /* - * FAN_RENAME is not allowed on non-dir (for now). - * We shouldn't have allowed setting any dirent events in mask of - * non-dir, but because we always allowed it, error only if group - * was initialized with the new flag FAN_REPORT_TARGET_FID. - */ - ret = -ENOTDIR; - if (inode && !S_ISDIR(inode->i_mode) && - ((mask & FAN_RENAME) || - ((mask & FANOTIFY_DIRENT_EVENTS) && - FAN_GROUP_FLAG(group, FAN_REPORT_TARGET_FID)))) - goto path_put_and_out; - /* Mask out FAN_EVENT_ON_CHILD flag for sb/mount/non-dir marks */ if (mnt || !S_ISDIR(inode->i_mode)) { mask &= ~FAN_EVENT_ON_CHILD; diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index 81f45061c1b18..4f6cbe6c6e235 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -113,6 +113,10 @@ extern struct ctl_table fanotify_table[]; /* for sysctl */ FANOTIFY_PERM_EVENTS | \ FAN_Q_OVERFLOW | FAN_ONDIR) +/* Events and flags relevant only for directories */ +#define FANOTIFY_DIRONLY_EVENT_BITS (FANOTIFY_DIRENT_EVENTS | \ + FAN_EVENT_ON_CHILD | FAN_ONDIR) + #define ALL_FANOTIFY_EVENT_BITS (FANOTIFY_OUTGOING_EVENTS | \ FANOTIFY_EVENT_FLAGS) -- 2.43.0